Irrlicht
Irrlicht (will-o'-the-wisp) is the German term for ghostly lights over bogs, called Irrwisch by Luther. Folk belief: souls of unbaptised children or drowned folk leading travellers astray. In Silesia, burying the light's source under a church eave and baptising it with rainwater could redeem the soul. Latin ignis fatuus coined from German in 16th century.