Didn't New York City even back then, have rent control? The Ricardos if I'm not mistaken, paid $125 month to Ethel and Fred. And he had at least six apartments.

Over the years, who did live there in Fred and Ethels building ? . I can think of the Fosters, Mrs Trumball, The Bensons, The oilman and his wife although they probably moves out after Lucy's had them pegged as scam artists. The funny episode starred K Stevens and Hayden Roarke where Lucy disguises her self as a chair. They probably didn't stay long either. Oh how about Albert/Alvin " Eat your lunch" where Lucy listened in the vents to find out about Grace Foster and Ricky. Bea Beneret's character who wanted to date Everett E Horton.

There was also the timid man who rented the Ricardos' apt. for a short time. He had just been a murder witness, i think.

He was the same actor who played the gondolier no one could remember.