"Fear in the Night" (1972) starring Judy Geeson, Joan Collins, Ralph Bates and Peter Cushing is a Hammer horror movie about a woman who moves in to her new husband's home on the grounds of a boys' school and keeps getting attacked by a one-armed stranger.
Peggy Heller (Geeson) is recovering from a nervous breakdown and has just married Robert Heller (Bates), a teacher at a boys' school in the English countryside. On the eve of moving to her new home, she is attacked by a one-armed intruder who has a prosthetic arm. Her landlady and new husband have a hard time believing her because there is no evidence and of her recent breakdown.
"Fear in the Night" is a film that slowly builds tension and mystery and takes place in the empty school and estate and keeps you guessing until the end.