Will-o' wisp, as I like to say it, are atmospheric ghost lights seen by travellers at night, especially over bogs, swamps or marshes. It resembles a flickering lamp and is said to recede if approached, drawing travellers from the safe paths. The phenomenon is known by a variety of names, including jack-o'-lantern, hinkypunk, and hobby lantern in English folk belief, and in much of European folklore.
The hinkypunk features in the Harry Potter games as a jumping ghoul carry a lantern, whereas the jack-o'-lantern or spook-lights is the US version. Usually the most common representation is in japanese folk lore as representations of broken lanterns, balls of flame or light, at times associated with graveyards and floating lights through the many forests in the country side; these are Hitodama (literally "Human Soul" as a ball of energy), Hi no Tama (Ball of Flame), Aburagae, Koemonbi, Ushionibi etc. All these phenomena are described as such, but occurring across Japan as a whole in a wide variety of situations and locations. These phenomena are described in Shigeru Mizuki's 1985 book Graphic World of Japanese Phantoms. They can be common with the protection of shrines and the English hobby lantern is even featured in the Studio Ghibli animations of Spirited Away and Pom Poko.
Folk belief attributes the phenomenon to fairies or elemental spirits, explicitly in the term 'hobby lanterns' found in the 19th century Denham Tracts. Briggs' A Dictionary of Fairies provides an extensive list of other names for the same phenomenon, though the place where they are observed such as graveyards or bogs, influences the naming considerably. When observed on graveyards, they are known as 'ghost candles'.
In European folklore, these lights are held to be either mischievous spirits of the dead, or other supernatural beings or spirits such as fairies, attempting to lead travellers astray. A modern Americanized adaptation of this travellers' association frequently places swaying ghost-lights along roadsides and railroad tracks. Here a swaying movement of the lights is alleged to be that of 19th- and early 20th-century railway workers supposedly killed on the job. Sometimes the lights are believed to be the spirits of unbaptized or stillborn children, flitting between heaven and hell. Modern occultist elaborations bracket them with the salamander, a type of spirit wholly independent from humans (unlike ghosts, which are presumed to have been humans at some point in the past).
