Ouija boards???

Last night, my son (20 years old), and a few of his friends were over. They were talking about going to the store and buying one. And I told them they were not allowed to bring it in the house. They asked me why, and that turned into an hour long conversation. A long time ago, we had a board, and we were using it, and I asked a question that only I... and I do mean that only I knew the answer to. And it worked, and it did for others around the table as well. I got paranoid, and that night I just wanted to get rid of the board. I wanted it out of the house haha.. I didn't want to throw it away for fear it would be a bad omen.. well I knew we were moving soon to another place, so I just put it in a closet, and when we moved, I left it there.. thinking "whew" Is there anybody else out there who has had an ouija board really work?? and if not spirits, what else could have made that thing move?