Found Reach-In Freezer Unit trips GFCI breaker right away before controller cycles through self test. Checked wiring only frame htr vaporizer and light powered off power switch. Vaporizer and frame heater good door light switch shorted to ground. Disconnected light circuit in control box will order new switch. Started unit. System operating properly otherwise. 9/26/18 Installed new door switch. Also tightened handle. Reattached wires in electrical box. Light now works. Back in service.