Gaslight

This thriller, first performed in 1938, gave rise to the modern term "gaslighting", describing a form of psychological abuse that causes the victim to doubt their memory, and even their sanity. Bella Manningham is haunted by the nightly unexplained dimming of the gaslights in her home and the mysterious footsteps coming from upstairs. Her husband Jack convinces her that these are mere hallucinations, and that if her mental state doesn't improve soon, he will have to take drastic action.