Ouija Board

A supernatural, or so it is claimed, game or toy. A group of people all press down on a wooden shuttle that rests on a game board that has numbers, letters, and the words yes and no. The group, by pushing down on the shuttle, causes it to move randomly and mysteriously. Supposedly, it finds its own path and spells out names and answers questions. Hence, it is available as a prop for mentalism & other magic acts.

The name is a trademark (dating back, it seems, to 1891) and is a combination of the French and German words for "yes" (Oui and Ja, pronounced "ya"). [Whether that is how it was invented is not certain.]

Probably second only to DungeonsAndDragons in terms of causing a great MoralPanic? among "concerned parents" () about being a tool of the devil, cultists, satanists, you name it. People actually seriously believed The Devil was controlling this thing, and some still do. I was among one of the crowd that believed that sort of thing, seeing Satan in everything from "backward masked" lyrics to Ouija boards... oddly enough I never bought into the condemnations of D&D even during the time when I believed all these other things.