Don Knotts and Tim Conway star in The Private Eyes, a 1980 comedy about two bumbling detectives solving a murder. It’s an impressively incompetent affair. Every ancient joke falls with a muffled thud as Knotts and Conway ham their way through the pointless story: The lord and lady of a capacious manor are killed, and the lord’s ghost seems to have returned to knock off the staff one by one. There’