Cameron's Closet (1988)

A young and lonely boy named Cameron (Scott Curtis) has telekinetic powers with which his father (Tab Hunter) experiments. The young boy's loneliness is the cause of a strange spell to be cast. A demon from hell is unleashed and tries to take over the boy's soul. A delusional police officer (Cotter Smith) and his new girlfriend psychiatrist (Mel Harris) are the only ones able to help the child after his father and mother's boyfriend (Gary Hudson) are killed. The demon lives in the boy's closet and in a part of the mind that can only be reached by entering it.