What is the name of this kid's TV Show?

There was this show I remember seeing, on Nickelodeon back in the early 80's. It had two people that worked at a theatre, or at least backstage. One lady and one guy. The show was always set at night, when they closed the theatre. Plus there was this weird janitor that was like a muppet or something. He was a short crank yankeresque guy with a mustach, hat, and a push broom. Can anyone remember watching it, and if so can you remember the name of it?