In 1957 Superman star George Reeves made a guest appearance on the I Love Lucy episode, Lucy and Superman. Lucy had promised that Superman would come to Little Ricky's Birthday party, but when he couldn't come due to a scheduling conflict, Lucy pretended to be him and got stuck on a ledge. Oh that Lucy.
The episode blurred reality as Reeves appeared in character as Superman but did not display any super powers, unless you count charm as a super power. Guess they didn't want anyone thinking that Superman was anything less than a true hero.
Check back next week for another chapter in The Super History of Superman.