I can't remember the name of this old movie can somebody help me?!

I can't remember the name of this old movie can somebody help me?

its about these nurses that are taking care of this guy who is sick or bedridden and there is a killer on the loose I think he kills nurses or something so I don't remember all the details but in the end of the movie the killer turns out to be one of the nurses dressed up to look like a nurse but he is actually the killer its an old movie I think from the 50's it was in black and white if anyone knows the name of it let me know the sick guy was in bed upstairs and the killer was one of the nurses dressed up the nurse was kinda big

Sounds like an episode from "Alfred Hitchcock Presents",
"An unlocked window"
imdb.com/title/tt0394099/
and was remade in the 1980s.