An electronic signal, sent through television screens, reduces people to their raging ”primal” selves. They’re not zombies — they are just murderously angry. Told in three sections (each with a different director), this Look Ma, no hands! And no head either! horror film makes a Mixmaster stew out of Poltergeist, Invasion of the Body Snatchers, Re-Animator, They Came From Within, and Shaun of the Dead. The Dada gross-out jokes are inventive, but The Signal mostly comes down to rage fiends going at one another with baseball bats, knives, pesticide tanks, and power drills. C+