Hello, I'm looking for the title of a movie from late 70.s or mid-80s. Babysitter left alone with kids, children are never seen, guy comes to door, says his car broke down, most of movie is back and forth at the door which she doesn't open until the last minute of the movie. She is wearing mid-calf length skirt and sweater, bowl haircut that halos her face, chestnut brown hair, sits in wing-back chair to study with heavy floor length green curtains behind her, door is just few feet away, she agrees to call auto club but phone is dead, wishes she could call her big brother, tells guy she called, he goes away, comes back, says he tried all other houses on street but no one home, she puts kettle on to boil, we see glass doors are closed, when tea is ready doors are cracked open, in last scene man comes from behind curtains with arms outstretched like a mummy.
I don't remember commercials but I can't find it in any movie list/database. Thanks!