Will-o'-the-wisp
The Jack o'Lantern

Mysterious lights which lead travellers away from their paths. In Wales, it was associated with the mischievious Pwca (Puck), while in much of the Isles, it is associated with the wandering dead, who are not allowed into heaven or hell. It is thought that this is the origin of the jack-o-lantern, which is a name given for the phenomenon in the West Country.

The origin usually involves a man who tricks the devil out of stealing his soul, but who is also too wicked to be let into heaven. He goes down to hell, but the devil doesn't want him and tells him to go back where he came from. The man begs for some light, so the devil throws a coal at him, which the man places in a turnip. Thus the jack-o-lantern is invented.

The scientific explanation is that the lights are either ignited methane, or perhaps ball lightning.

The lights seem to have usually been associated either with the dead or with fairies; in some tellings, the light is to welcome the dead back to the house for a dumb supper, or it was used to frighten away ghosts or fairies. Also, when trick-or-treating, bands of boys dressed as women called gwrachod (hags) would carve out turnips and use their lights.

Other names include: