The horseshoe is prevalent in common folklore. In folk-magic it is used to keep away witches, fairies, the devil, demons and the evil eye throughout the British Isles Europe and Arabia. When nailed over a doorway of a house, church, building or stable the iron content was thought to prevent the witch from crossing the threshold.When placed in a chimney it supposedly kept a witch from flying on her broom. When nail over one’s bed it repelled nightmares and demons. To be effective the horseshoe must never be remove once it is installed. In Ireland, in similar manner, it is used to keep away fairies.

The horseshoe also is employed as a charm of good luck; although, the same horseshoe cannot be used for both, a good-luck bringer and a demon-repellent. When used as a repellent the horseshoe should be positioned with its ends down; but, when used as a good-luck charm then ends should be up so the luck will not run out. A.G.H.

Source: 4.