I don't think toying around with the spirit world is a good idea, even if you don't think they're real. Even if you don't believe demons exist, which is fine, if you're willing to try and provoke one, then you have to have some form of recognition of what they are. Christianity isn't the only religion that recognizes these evil spirits, so perhaps there's logically some merit to this stuff, right? So you get yourself an ouija board, grab your friends, and together you try to provoke these spirits to come out. Nothing happens. That's unquestionably the best result you can get out of one.
If you don't believe demons are real, that's fine. But if you're willing to provoke one into coming out, then be prepared to deal with what they really are. I only say this because either nothing will happen, or extremely bad things will happen; nothing good can possibly occur in the event you're wrong. According to the Bible, demons are fallen angels. They're immeasurably powerful, manipulative, hate-filled spirits who would like nothing more than to destroy you in every sick, twisted possible way. Thankfully, they're also bound to the will of God, and can't touch you so long as he doesn't allow it. But, if you keep knocking on their door, eventually God might allow one to answer, and it won't be pretty. As Christians we're warned not to meddle with the spirit world, because on our own we're completely powerless to stand up to what's on the other side. I recommend to others to also do the same.
I don't say this as some crazy, religious forum poster, but with the intent to be a voice of reason in this. Even if you don't believe they exist, which is fine, logically nothing good can happen if you do happen to provoke one into coming out.