Get Smart (1965)

S1E11 Too Many Chiefs

Master impersonator Alexi Sebastian is on a mission to eliminate Tanya Lupescu, who holds the key to the KAOS coding system. To create chaos, he disguises himself as the Chief. Meanwhile, agents Max and 99 are tasked with protecting Tanya, who has memorized KAOS' codebook. After a failed hotel hiding attempt, CONTROL decides to stash her in Max's apartment. However, KAOS recruits Alexi, who has previously impersonated Johnny Carson and Max's Aunt Rose, earning a shoot-on-sight order. Disguised as the Chief, Alexi infiltrates the apartment, leading to a tense moment when the real Chief arrives, leaving Max to figure out which one is which.