Given the timeframe, that it was late night, and the description, it sounds like something from one of several horror anthology shows that were popular then, like
Tales from the Darkside or
Monsters. I don't know the movie/show you're talking about, but that's probably a good place to start. One of our members did a thread about anthology shows a while back, complete with the years the series' ran. If you look through his list you can find anthology shows from that time and research them. Here it is:
http://www.badmovies.org/forum/index.php/topic,135797.0.html