Wes Craven's Shocker takes media manipulation to a new level in this story of an evil force emitted from television sets that has the power to kill. The film centers on high school athlete Jonathan Parker (Peter Berg). His estranged father is homicide detective Don Parker (Michael Murphy), who has been working on capturing an elusive serial killer plaguing the town. One night, during a particularly vivid nightmare, Jonathan dreams that while Parker is away on an assignment, his family is murdered by the serial killer. In the dream, Jonathan can identify the killer -- local television repairman Horace Pinker (Mitch Pileggi). Amazingly, it turns out that Jonathan's nightmare was reality. Using Jonathan's dream as evidence, Pinker is brought to trail, found guilty, and sentenced to death in the electric chair. Before his execution, Pinker makes a pact with the devil so when he is electrocuted, the electricity from the chair will give his spirit powers of evil. At first, Pinker's murderous spirit travels in and out of people's bodies, prompting the host to commit murder. But when it seems more effective to communicate with people by television signals, the spirit is willing and soon people suddenly become possessed by Pinker's spirit through TV screens and engage in murderous atrocities. All this is done by Pinker to exact retribution upon Jonathan, who was responsible for sending him to his death.
~ Paul Brenner, All Movie Guide