There are skeptics who claim that the planchette of a Ouija Board is controlled by the living beings interacting with it. There are believers who suggest that a Ouija Board opens a doorway to hell which lets demonic forces enter our world.
My thoughts are more similar to the skeptics than the believers. I don't believe there are demonic spirits -- all spirits have an unwelcome temperament. And I do concur that the planchette is moved by the contractions of muscles within the hands of those using it -- but those movements are subconscious. Tie a string to a small object, like a crystal or a fishing weight, and swing it forward and backward, mentally telling yourself this means "yes", then side to side, telling yourself this means "no." Then ask the Universe a yes or no question. Before long, you will notice the weight will swing in one of the two directions -- all without your awareness that YOU are controlling the swing of the weight. Again, this is a subconscious act. Why is this important and what does it have to do with ghost hunting? Because it is how we fish for ghosts. Subconscious acts are created beyond our minds, they emanate from the soul. As the covert signals travel from the soul to our bodies, tiny vibrations radiate out into the cosmos. These vibrations attract ghosts.
If you have used a Ouija Board for more than two hours, ghosts will be present. They will not be able to move the planchette because you are touching it. Have everyone sit back about four feet from the board and ask a question to the room. You might be surprised at what happens next.