The small village graveyard called Evergreen Cemetery in St. Paris, Ohio, contains a notorious glowing tombstone. Nearly a thousand people have crowded the cemetery on a single night, hoping for a look at the famous McMorran family marker and its faint but undeniable luminescence. Theories include a phosphorescent fungus and reflected light from the village, but none have definitively debunked the strange glowing stone.
Gerrick, David J. Ohio's Ghostly Greats. Dayton: Dayton Press, 1982. pp. 16-17.