Anyone Know This Movie???

Hi! You guys seem to be so good at knowing scary movies from the 70's (yes, I too was happily traumatized by these movies as a child), that I was wondering if anyone knows what this movie might be:

It must have been a movie of the week kind of thing, because my babysitter was watching it on TV and that was before movie channels and videos. I would guess this was about 1973 or so, although it may have been made earlier and replayed.

The movie involved a guy that was dressed like a demon or faun who was running around and posing in a place that looked like a library or stage or could have been someone's apartment (although a very elaborate apartment). I know that's just a snippit, but the thing that really stands out in my mind is that this guy was dressed up like a faun or Goat Man or Greek Pan or forest sprite or something like that. I'm trying to remember, but I think the story was set in the modern day (which would have been the 70's, back then) and I think I remember a man and a woman, possibly parents or brother/sister/friends talking about how concerned they were about this guy. I don't know this for a fact, but I think possibly this guy was in a play, such as Shakespeare's Twelfth Night (sorry, I don't think I spelled that right, but I guess it's late -- you know, the play they did in PORKY'S 2), and maybe he started thinking he was the character and basically went crazy, etc.

Does this sound even remotely familiar to anyone?

Thanks,
Kathy