Will-o’-the-wisp is a ghostly, bluish light sometimes seen over marshes and graveyards. Scientists believe it is caused by the natural burning of methane (marsh gas) produced by decaying plants. Will-o’-the-wisp is also called jack-o’-lantern, foxfire, and ignis fatuus, a Latin term that means foolish fire. Will-o’-the-wisp often seems to move away or vanish when approached. It was once thought to be a spirit that enjoyed misleading travelers. People who followed such a light would suddenly find themselves hopelessly lost in a swamp. In several English legends, the hero turns one of his garments inside out to magically end the power of will-o’-the-wisp. Other traditions speak of will-o’-the-wisp as the soul of a dead person.
