Is this the movie?...

I have a vague childhood image of a woman in a shower, then a evil looking man in a cape sneaks into the bathroom and (I guess) turns on the gas(or something). She passes out, then a couple minutes later another man saves her by carrying her out into fresh air. I saw this scene in the early 70's on the ABC-TV movie. It scared the crap out of me, I went back to taking baths for awhile. ABC-TV used the same movie intros until the 1980's, I always associated them with that scene. Is this the movie I remember?