Anthropologist Bruce Grindal recounted an incredibly spooky experience he had among the Sisala people of northwest Ghana: A drummer had passed away, and many of the people gathered to sing songs and dance around the corpse. All of a sudden, Grindal witnessed the corpse rise up and dance to the beat!
Grindal, by his account, had slept poorly and eaten little prior to this event, and his weary state certainly could be partially responsible for his hallucination (as well as the hypnotic rhythm of the music being played).
I definitely recommend reading Grindal’s harrowing account in full, it’s well worth it. It also strikes me as an excellent counterpoint in resurrection-of-Jesus debates. When presented with evidence of mass hallucinations like this one, apologists often reply, “Well, how do you know it’s a hallucination? Maybe something supernatural really happened!” In this case we have a really excellent reason to believe this was a hallucination. Grindal reports the conversation he had with a tribesman the next morning, in which the tribesman reveals that “Some did and some didn’t” see the resurrected drummer boy (p. 69).
Grindal’s paper may be read here if you register with JSTOR (which is free).