Have a screw loose

Richard, glorious in new livery, [...] went with his sad message, first to the church and then to the banqueting-hall in Albemarle Street. "Not any wedding?" said the head-waiter at the hotel. "I knew they was folks as would have a screw loose somewheres. [...]"

"You know he really has got a screw loose in his head somewheres, an' there ain't any one but what says he's the town fool, all right."

Pete Campbell (Vincent Kartheiser) would be just another irritating office brown-noser, a prep school Sammy Glick, except that he too has a screw loose and a mystical rapport with firearms.

"A successful murder has to be 'attempted' in the first place." "We both know what matters here is how you perceive the meaning." "Any immortal who considers that a loophole has a screw loose." "For all I know, your screws..." "I vow to not do anything with the intent of Elliot getting killed, okay? Leave my screws out of this."