One of the weirder movies starring Chevy Chase.

Plot summary from IMDB

In World War II era Los Angeles, the manager of the Culver Hotel leaves his nephew in charge for a weekend. The nephew changes the name to the Hotel Rainbow and overbooks with royalty, assassins, secret agents, Japanese tourists, and munchkins (from the cast of The Wizard of Oz (1939)). Secret Service agent Bruce Thorpe and casting director Annie Clark find romance amidst the intrigue and confusion

(Thanks Elbow-Toe!)