My wife (then fiancee) and I found something similar in the attic of an apartment building in Cincinnati. Didn't have to go through a wall and it wasn't locked,

My wife (then fiancee) and I found something similar in the attic of an apartment building in Cincinnati. Didn't have to go through a wall and it wasn't locked, but once inside the attic had low ceilings and looked untouched since the 1920s. I'm sure people had been up there but it was full of antiques and had what looked like original wallpaper everywhere. Very old rotary light switches too.