Nature, superstition, illusion, jack-o'lantern, ignis fatuus
Description of this motif: Will-o'-the-wisps are ghosts of unrighteous people, who with their light attempt to decoy people to get lost and to get them to walk into swamps. – so wrote J.M. Thiele in Danmarks Folkesagn (1843-60), 1968, vol. 2, p. 238. Will-o'-the-wisps are usually only rather insignificant in Hans Christian Andersen's tales. In The Will-o'-the-Wisps Are in Town they play a main part, though.
The tales are sorted by year. The leading numbers refer to the number of occurrences of the motif in the respective texts.