In what amounts to more fair warning than you normally expect from Hollywood, "Ernest Scared Stupid" opens with Ernest P. Worrell in a pile of garbage. The recycled trash that follows is, therefore, no surprise.
When last encountered, in "Ernest Goes to Jail," Ernest had entered a plea of inanity and was in the slammer. Unfortunately, he's now back on the streets, free to continue his one-man dumbing of America. In demeanor and deportment, Ernest still looks like someone you might find passed out under the stadium seats in the final quarter of a pro football game. The difference in his fourth misadventure is one of degree.
In "Ernest Scared Stupid," it is explained, the Worrell family fell under an ancient curse which ordained that each succeeding generation would be more cretinous than its predecessor. This premise sets up the terrifying prospect that there is someone even more moronic than Ernest in our movie future.