Holy cow, MB, I remember both of those, too, now that you've brought up their titles! The music for She Waits was particularly "eerie" and had a DS-tone to it.
Another one, which is more of a thriller than a horror, although it's frightening, from that era, is Bad Ronald. It's about a young teenage boy, fat and ugly, horribly bullied, who accidentally kills a girl who was tormenting him. His widowed mother hides him in their home by closing off a first-floor bathroom and it initially works. However, his mother dies and he's left alone in that house until another family moves in, not knowing about the secret room and "bad" Ronald living in it who can come and go through a passage. There were scenes that truly turned one's blood cold.
It truly was a golden age, throughout the seventies and into the early eighties (with some notable exceptions extending into the nineties), of well-done, creepy, classy, elegant made-for-TV horror movies.
Gerard