This is the story of Max Jenke (Brion James), "the most feared mass murderer in American history," and Lucas McCarthy (Lance Hendriksen) the detective who brought him in. Max gets the chair in the first few minutes of the film, but that doesn't even slow him down, because back in his room (which the cops apparently never searched, and which the landlord hasn't cleaned or re-rented) he had his own electric chair. Max practiced up with low voltages so that he built up an immunity, you see....
Lucas has been having nightmares about Max for a long time, and the dreams don't stop with Max's death. In fact, Max has transformed himself (and, presumably, his meat cleaver) into a form of evil electrical energy. At least that's the theory propounded by Professor Campbell (Thom Bray), a gentleman who delivers his lines as if someone were holding a gun to his head. This evil energy goes to the McCarthy house, where it possesses the oil furnace, possibly because possessed baseboard heaters aren't very spectacular.
Once he's in the house with Lucas' wife and kids (a not-bad looking daughter who takes showers for reasons unrelated to the plot, and an obnoxious son whose hobby is getting free food from manufacturers by complaining of contamination), Jenke commences his reign of terror. The reign of terror is pretty simple. Someone will go down the basement steps (this film should have been called UPSTAIRS, DOWNSTAIRS for all the long tracking shots of people going from the first floor to the basement, and back again), he or she will walk around for a while, there will be a sudden noise, the victim will jump, then five seconds later the real scream-and-leap comes.
This could have been an effective is-Dad-going-nuts movie, except that we-the-audience know that Jenke's really there: we saw him arrive with blazing lights and electric discharges.
Jenke, it seems, can alter reality. There is a major problem with a movie where absolutely anything can happen: you wind up not caring what happens. True, there are some well done bits: the talking roast turkey is good, and the Death-a-thon television show is funny. But isolated bits can't save the film.
In the end, McCarthy kills Jenke by shooting him, rather than electrocuting him. Too bad for Jenke that he hadn't built up an immunity to gunfire, too, by shooting himself a little bit every day. The final bullet hit, where McCarthy puts his gun in Jenke's mouth, takes place off screen, missing a real opportunity for splatter. As an aside, in a hostage situation, when the perp tells the cop to put down his gun, real cops don't put down their guns. Lousy police procedure.
Sean Cunningham (of FRIDAY THE 13TH fame) produced, and James Isaac directed, from a screenplay by the infamous "Alan Smithee" and Leslie Bohen. THE HORROR SHOW ends up being less than the sum of its parts.