Security guards, the clumsy and overweight Chuck (played by Gailard Sartain) and the reserved Bobby (portrayed by Bill Byrge), entertain themselves during their night watch at Howard County Bank and Trust by playing a game of Red light/Green light, their minds racing with outlandish schemes to catch potential thieves. One night, they hear a commotion from a floor polisher, where Ernest P. Worrell (embodied by Jim Varney), a night custodian who aspires to be a clerk, struggles to operate the machine, inadvertently causing chaos within the bank as he becomes magnetized due to a mishap.
The following day, Charlotte Sparrow (played by Barbara Tyson), the assistant to the bank's president Oscar Pendlesmythe (portrayed by Dan Leegant), demands that Ernest clean up his supernatural mess. President Pendlesmythe is determined to fire Ernest, but Charlotte, possessing a soft spot for misfits and lost causes, defends him passionately.
In his home, Ernest hilariously takes a bath in a tumble dryer and uses a blow dryer set to wind tunnel strength to prepare for his dinner date with Charlotte at a restaurant. During this time, he also informs the two watchmen about his jury duty summons.
During the jury trial, a convict from Dracup Maximum Security Prison, Rubin Bartlett (played by Barry Scott), recognizes that Ernest closely resembles the death row inmate, Felix Nash (a dual role also played by Jim Varney). Bartlett's lawyer manipulates the jury into allowing a tour of the prison, where Nash and another inmate, Lyle (played by Randall 'Tex' Cobb), kidnap Ernest and coerce him into swapping identities with the incarcerated felon. Despite tirelessly protesting his innocence, Ernest finds no one believes him, and he remains oblivious to his predicament involving a death sentence that has been placed on Nash.
During lunch, a guard demands silence, and when Ernest inadvertently makes noise, he nearly faces punishment. He desperately tries to convince the guards that he is not Nash, but is only met with hostility and disbelief, leading to him being thrown into a cell. There, Lyle pushes him back as he tries to defend himself, while the guard misinterprets the situation, unknowingly causing Ernest even more trouble. Bartlett informs Ernest that Nash has usurped his identity, advising him to remain silent to survive.
As the situation unfolds, Ernest attempts to escape multiple times but finds himself on death row, facing the electric chair commanded by the warden, Charles Napier. Strangely enough, the electrocution goes wrong, transforming Ernest into a superhuman who develops the extraordinary ability to shoot lightning bolts from his hands, calling himself 'Electroman.' He dramatically blasts through the prison gates in an attempt to escape, but Bartlett tries to thwart him, only to be stopped by Lyle, who recognizes the uniqueness of Ernest and allows him to flee.
On his way home, Ernest is shocked to discover that his home decor has been transformed into a flashy Lounge Lizard style, exclaiming, "I've been vandalized - by Elvis!" Meanwhile, Nash plots to detonate the bank's vault with a time bomb, with Charlotte and the hapless Chuck captured nearby. Charlotte pleads with Nash not to proceed, but he accidentally reveals his true identity as an impostor. Initially skeptical, Charlotte begins to believe him when he points out the improbability of Ernest’s cleaning efforts compared to his own.
As Ernest confronts Nash, they engage in an explosive showdown. Ernest faces electrocution yet again and gains the ability to fly, propelled by his newfound powers. Soaring through the bank's skylight with the bomb, he culminates in a spectacular mid-air explosion that surprises everyone, including Chuck, who fears Ernest has perished. However, Ernest dramatically crashes through the skylight, landing atop Nash, leading the warden and guards to realize the truth in his claims. Tired and bewildered, Ernest declares, > "I came, I saw, I got blowed up," before fainting from exhaustion.
