Similar story, year was 1981; we “played” with the Ouija board for several months but grew tired of it after a while. One night three of us were making fun of it at 3:00am when we heard three loud bangs on our basement door, coming from the basement. So loud they could have splintered the door. We went through the basement with kitchen knives and pellet guns but found nothing. Two weeks later my mother tripped over the stairs at the very spot where the bangs originated; she broke her neck and died on the stairs.
We didn’t have Google back then, but Google “three knocks” and see why this causes the hair on my neck to stand on end 30 years later. Tough to rationalize this as a lifelong atheist; had I not experienced it myself the world would be a simpler place. As it stands, I have to pretend it didn’t happen to maintain any sense of reality. The implications are frightening.