Desire and Hell at Sunset Motel.

Right after Disneyland opens in Anaheim, California, in 1955, a toy salesman in town for a convention brings his wife with him so they can both go to Disneyland. They stay at a rundown place called the Sunset Motel nearby. Soon the wife is having an affair with a man staying at the motel. The husband hires a psychotic criminal to spy on them, the wife and her lover plan to murder the husband, and the voyeuristic motel manager is spying on everybody.