Shawn (and Gus) of the Dead Psych : Season 2 Episode 16

Lassiter and Juliet get called to a museum to investigate the disappearance of a 3,000-year-old mummy. Lassiter insists it's just a prank that's not worth his time. He's busy working on another case involving the death of philanthropist William Wyles III. However, the assistant curator insists that something weird is going on, something possibly supernatural that requires special help. Shawn is then brought in on the case, and he declares that the mummy was not stolen, iit walked away on its own.