I do believe in energies, spirits and ghosts, and that we're surrounded by them every minute of every day. Having said that, I do not believe that most people using a Ouija board have made contact with them. I think that most of the time someone is moving it, or that you are unconsciously moving it yourself.
My mother would not allow one in her house, due to some experience that's gone unexplained to this day.
I used to play around with them a lot in high school. We would also play the game where you sit across a piece of paper from eachother, a pen held in your clasped hands and you drew back and forth in a line until the pen started to write on its own.
Anyway, one time we were having a slumber party and I was upstairs in my room. Another girl ran to come get me, claiming that there was something going on that I had to see. The girl who was my best friend at the time was sitting in front of the board, with her hand sitting above the playing piece. She was talking in a sort of weird, funny voice, and she said some things that I'm not going to repeat here, but I bought it. In retrospect, I'm not as sure as I used to be about it. We would always ask the Ouija who we were talking to, and azaz was the one we usually got. He said all these things about past lives and things that are owed. He also claimed that he liked to watch me, which still creeps me out if I think about it too much today.
I haven't played with one in years, and with the late hour and my terrible nightmares, I think I'm going to just hit "add reply" and try to forget about it tonight.