My sister, who was a law clerk for a judge named Katz, was asked on the phone if she was (someone she wasn't). No, she said, I'm one of judge law clerk's cats. And promptly hung up in embarrassment.

That same sister's (then) husband, answering a different phone, when asked if he was Mr. (her name), said No, Mr. (her name) is my wife, and promptly hung up in embarrassment.

That last one wouldn't be as embarrassing today...

I am also reminded of the James Thurber cartoon with the predatory-looking woman on the couch with the phone, and the Mittyesque husband looking over his glasses at her, captioned Well, if it was a wrong number, why did you answer the phone?