How does the Ouija board game work?
If you want to know "how it works", it works based on the IdeoMotor effect: not spirits and ghosts of days past. Remember it is a GAME and a TOY developed and manufactured by a game and toy company.
The ideomotor effect refers to involuntary and unconscious motor behavior. The term "ideomotor action" was coined by William Carpenter in 1882 in his explanation for the movements of dowsing rods and pendulums by dowsers, and table turning by spirit mediums. The movement of pointers on Ouija boards is also due to the ideomotor effect. It's just a toy.