Dial M for Murder (1974)

Anthology of crime stories in which the telephone plays a key role...Glamorous model Suzanna (Sharon Maughan) marries the only son of wealthy American widow Geneva (Elaine Stritch). On the surface life seems to be perfect until Suzanna starts to get anonymous telephone calls...Jean Browning (Isabel Dean) leaves husband and moves to a mews house, in London. Her new cleaner turns out to be a recently divorced man. They spark up a friendship but soon his behaviour starts to change...Beth (Brenda Bruce) runs a telephone message service with a loyal bunch of customers. When a client's wife is involved in a car crash she makes the decision to go and visit him, only to discover he is a hit man...