Bumbling Ernest P. Worrell is assigned to jury duty, where a crooked lawyer notices a resemblance with crime boss Mr. Nash, and arranges a switch. Nash assumes Ernest’s job as a bank employee, while Ernest undergoes Nash’s sentence to the electric chair. But instead of killing him, the electrocution gives Ernest superhuman powers, enabling him to escape from jail and foil Nash’s attempt to rob the bank.

Well-intentioned, eternally bumbling Ernest P. Worrell accidentally releases an evil demon from its sacred tomb. As the demon flexes its power and goes on a ruinous rampage, good-guy Ernest tries to step in to save the town from mass destruction. Trouble is, a 200-year-old curse has scared Ernest stupid, and that means hilarity all around! So, kick back and let the laugh-ridden adventures begin.

A group of juvenile criminals is sent for vacation to Kamp Kikakee. The clumsy Ernest has to care for them, although he doesn’t even know how to take care of himself. The other children at the camp show enmity against them, but the group knows very well how to defend themselves. They do also help the Indian owner of the camp when a brutal mining corporation wants to tear down the camp to mine a rare mineral.