Not the hallucinations. If you know at least a little of what you're dealing with doing this especially at night alone may seriously cause you to hallucinate. It's a psychological trick of triggering panic into someone. Most people who used to ouija board without knowing what they are getting into experienced this. I know this happen to a lot of people local here so I know that the hallucination is not just a theory. It can drive you nuts if it's something heavy. The first time I used an ouija board(which was at school) I remember doing something in class and the teacher was talking to me and I wasn't conscious at all I was just looking into my bag like some weirdo.
So what I'm saying is to be wise, be brave, don't ask stupid questions, don't constantly do it alone(I do it alone but not as much anymore cause I know the experience is less pleasant when alone), and if a friend doesn't want to don't force him/her.
Spirit communication(channeling) is a risky psychological thing for even the most skeptical person. So hear me out.