My Apartment is Cooler than Your Apartment

I live in this cute little art deco style apartment building which contains 15 little studio apartments.  I have a full kitchen, dining room (complete with little chandelier), a Murphy bed in my living room, and my closet isn't a closet but a dressing room complete with built-in vanity.  My stove looks like something out of Leave it to Beaver, and the black and white subway tile in the bathroom is too charming for words.  All my doorknobs are these little frilly acrylic things, and the vanity mirror has the cutest floral embossing at the top.  Next to the mirror there's this little button embedded in the wall, and I've never been able to figure out what it was, but had sort of given up assuming it used to be an old-school electrical outlet for a vintage hair dryer or something.

Well, I ran into my neighbor at the gym yesterday and we were talking about our building when she said, "Well you know what it used to be, right?"  Aghast and curiosity piqued I replied, "No!"

"It used to be dormitory style housing for young starlets being groomed by the big studios!  ...Yeah!  And you know that little button that's on your vanity?  It was a buzzer they would ring when they were ready to have their hair done."

I mean...  I'm never moving.