"But there are many entities pretending to be what they are not."

YES. This is the precise reason why I don't use Ouija boards, nor will I ever conduct a séance. There is something about channeling non-embodied entities in groups that is extremely dangerous, and I notice that lots of mediums take zero precautions when they do Ouija sessions or séances. It's basically like a bunch of people going into a seedy bar and then stripping naked and inviting strange men into the bathroom to do whatever they like to you and your friends. Gross.