All through the Germanic world, we have the belief in house-ghosts. These wights are called by different names - nissen in Denmark, tomten in Sweden, tussen in Norway, kobolds in Germany, among others - but they seem to be all of the same sort. In Scandinavia, the house-ghosts are usually seen as little men, often wearing gray clothes and pointed red caps; the Danish nisse is also said to be thumbless. As with the beliefs in alfs and land-wights, the belief in house-ghosts long outlived the worship of the Ases and Wans; the custom of putting porridge out for the tomte or nisse has lasted to the present day in Scandinavia, although non-Heathen households take it no more seriously than they do putting out cookies and milk for Santa Claus.
One of the Norwegian names for the house-ghost is haugbo (also appearing in Orkney dialect as hogboy) - "howe-dweller" or haugbonde, "howe-farmer". Sometimes nissen or tomten are also said to live in mounds on the land. In "Gardvoren og senga hans", Solheim suggests that the house-ghost was the first owner of the farm, who dwells there as the embodiment of its prosperity - and perhaps to make sure that things are done rightly by those who come after him. This suggests that the house-ghosts of modern Scandinavian folklore may be much the same as the wights the Old Norse sources knew as alfs - the ancestral mound-dwellers who look after their kin. This idea may also be strengthened by the fact that the house-ghosts are always, with no recorded exceptions, male.
The house-ghosts are not always tied down to their mounds, however. While some are strongly associated with places (particularly communal places, even making their home in churches), many others will cheerfully pick up and follow a family where-ever it goes, whether they are asked to go or not. The theme of a family that tries to change houses to get away from a troublesome house-ghost, only to see him sitting on top of the wagon and chuckling about what a fine day it is to move is widespread through both Scandinavia and Great Britain (where it is attributed to the Gaelic brownie as well). Such wights also guard ships, mills, and other places where folk work - your office may have its very own house-ghost.
The chief role of these wights is to take care of the house and its surrounding lands. In rural households, they make sure that the bread rises, the cream turns to butter in the churn, the cows are fed well, and the field-work is successful. Today, most of them have different ways of looking after the families they follow. House-ghosts make sure that your keys and glasses are where you can find them, that the house's wiring is safe, and generally that things go as they ought. They help with cleaning and garden-work; they are annoyed by lazy people, but make things easier for the hard worker.
The house-ghost is also particularly responsible for bringing luck to the household, sometimes by stealing it from other households. One story from Denmark describes how a farmer had no fodder for his cattle, but his nisse went out at night with a cow and brought her home loaded with hay (Kvidelund & Sehmsdorf, Scandinavian Folk Belief and Legends, pp. 239-40). Another tale from Norway, variants of which appear all over Scandinavia has a man seeing his tusse struggling with a blade of grain and laughing at how light the load is. The tusse replies that he will see soon enough how heavy the burden was, and turns around to carry it the other way. After that there was nothing but poverty, illness, and bad luck on the farm, because the tusse was carrying all the good from it.
These wights work tremendously hard as long as they are appreciated, and ask little in return - a plate of porridge and a glass of beer every Thursday, with a share of feast-food on holy days, will usually keep them very happy indeed. In the last couple of hundred years, it has been found that they like tobacco as well. They are also fond of whole milk (though not skimmed, which will make them unhappy because they think you are being stingy with them - house-ghosts do not understand about cholesterol), and KveldúlfR Gundarsson has found that his house-ghosts like vodka and other sorts of schnapps as well. If you think of your house-ghosts as old folk from rural Scandinavia or Germany and ask yourself what they would have wanted to eat or drink at home, you probably can't go too wrong. This food is either put in the barn or stable, where the house-ghost usually lives in rural households or beside the hearth (Diana Paxson suggests having a stone there to serve as his dwelling, on which the plate of food can be placed). If you have no hearth, the stone should go in whatever place you have chosen as the heart of the house. Grimm tells us that the house-ghost's yearly wage, given to him on Yule morning, was "grey cloth, tobacco, and a shovelful of earth" (II, p. 512).
One must take leaving the food out for the house-ghost very seriously. There are a number of tales of folk who ate the house-ghost's porridge themselves and/or defiled his plate, with consequences ranging from his aggravated departure to the culprit being beaten to death. It is especially important to give the house-ghost his food at Yule (and probably Winternights as well, since he will just have finished a long and hard stint of work). House-ghosts often revenge slights violently, and since they are supposed to be very strong in spite of their size, this is something to be wary of.
House-ghosts also dislike noisy evenings, although the nisse is fond of music. If you are planning a raucous party, you should probably warn your house-ghost beforehand, and give him fitting food and drink before and after as a reward for his tolerance. According to Swedish superstition, the tomte particularly hates chopping in the yard on a Thursday evening (Grimm, II, p. 509), and probably dislikes any sort of disturbance on this evening, as it is the night on which he gets his porridge and beer, and presumably his night off.
One of the most common stories about house-ghosts is also told of brownies in Scotland: the folk of the farm see their house-ghost dressed in tatters, and either feel sorry for him or want to reward him for all the hard work he has done for them. They make a little set of clothes, which he puts on with delight, declaring that now he is too fine to do farm-work, and they never see him again. However, other sorts of gift were apparently customary in Germany: clause 103 of the Penitential of the German Church (ca. 900 C.E.) asks, "Did you make bows and shoes of a size that small boys would use; and, then put them in your cellar or barn for satyrs and goblins to play with so that they will bring good things and you will be made richer?" (Chisholm, James, tr., Grove and Gallows, p. 54)
House-ghosts can often be mischievous, and like to play tricks. If they become obnoxious, an extra gift of food or drink put down with the firmly placed request that they kindly stop doing whatever has been annoying you is the best way to get them to stop. Actively banishing them is the very last resort, as a well-meaning house-ghost is the best and truest friend you can have. Most of those that become obnoxious simply do not realize that they are upsetting their people, and once told, become contrite and more helpful than before.
Other sorts of requests can also be made to the house-ghosts together with gifts of food and drink - the most common being, "Would you kindly find this/that/the other for me?"
Some house-ghosts, however, are basically unpleasant. There are Icelandic families even today which suffer from horrid wights called fylgidraugar (following-undead). These wights are a type of Sending made out of babies abandoned to die, which stay through the generations to torment a family. The best that can be hoped from these is that, if they are given food, they will be less obnoxious than if they exert their whole strength to make trouble.
There is an Old High German charm to banish ill-willing house-ghosts:
"Wola, wiht, taz tu weist, taz tu wiht heizist,
Taz tu neweist noch nechanst cheden 'chnospinci'."
(Well, wight, do you know that you hight 'wight',
that you do not know and cannot say 'chnospinci'.")
The wight, rather like Rumpelstiltskin, becomes so furious at not being able to pronounce the nonsense-word "chnospinci" (chno-speen-kee - the chn is a sneezing sort of sound), that it departs at once in a huff. This charm is only to be used when all else has failed.
In rural households, the house-ghost often chose a favourite horse or cow to give extra care and fodder to - the fodder being stolen from the other beasts. If one of your pets is always fat and sleek while others seem thin and unhappy, and (the most important step in diagnosing the problem) a vet can find nothing wrong with the ones that are not faring as well, it is possible that the house-ghost is interfering with them. In that case, his unfortunate victims should be fed by themselves and given extra care by the owner. In one Swedish tale, a farmer sold the tomte's favourite horse and brought another one, which became thinner and more sickly every day. One night the farmer hid in the stables, and saw the tomte come in and flog the new horse with a big whip. He then bought the old one back again, and had no more trouble (Simpson, Scandinavian Folktales, p. 174).
The house-ghost is especially associated with cats: Grimm mentions the names polterkater (noisy tomcat) and katermann (tomcat man) for him (II, p. 509), and says that the cat shares the name Heinz and Heinzel with the kobold, as well as being a stiefel-knecht (boot-servant), "coming very near the resourceful Puss-in-Boots. The tabby-cat brings you mice, corn, and money overnight; after the third service you can't get rid of her...A serviceable tom-cat is not to be shaken off" (IV, p. 1432). Treating house-cats well is clearly very important for the prosperity of the home.
Grimm also mentions the custom of having carved kobold-figures in one's home or painted on the wall (II, 501-02). Such a figure might well serve as a dwelling for the house-ghost, before which his food and drink could well be placed. If you seem to have no house-ghost, such a figure could well be used as the focus for a rite to call one to you, as suggested in Gundarsson's Teutonic Religion. If you look closely, you may even find that you have a statue somewhere in your house which has attracted such a wight on its own.
Finally, it must be mentioned that in her humorous fiction, the writer Esther Friesner has advised against letting tomten see Ingmar Bergmann films, which throws them into deep Scandinavian depressions. There is probably no real basis for this...but just in case...