There’s nothing to be concerned about with Ouija boards. it’s been shown, even with people who believed in them, that if you blindfold all the participants, it doesn’t work.
There is no power in a Ouija board, but using a Ouija board is dangerous because it invites any spirit that happens to be hanging around to come and take partial possession of your subconscious mind. Passiveness, eagerness to receive, and indiscriminate acceptance are especially dangerous, because they are an open invitation to every spirit that has an agenda. You may take my word for this or not, as you please, but I proved it for myself by experience.
But even if they don't "work," they are used to in the very least to attempt to contact the dead, which is explicitly forbidden in the Bible.