if left over night kills batterie
why clicking in dash causes locks activate on there own and car not running on 2003 Chevrolet Cavalier
Possible loose wiring causing a parasitic drain. Probably best to take to a shop to locate the wiring issue.
It's possible one of your door lock switches is failing and sending a false lock command. Have the car checked by a shop.
agree with both poss door lock relay or module issue