Gas Light(1939)

Gaslight is a psychological thriller about a young woman who returns to the house where her aunt was murdered years earlier, now married to a charming stranger. Her husband harbors a dangerous secret tied to the crime, and he'll stop at nothing to keep it hidden—even if it means systematically manipulating her into questioning her own sanity. As his gaslighting intensifies, she must uncover the truth before she loses her grip on reality. The film explores the dark psychology of control and deception within marriage, building tension through the husband's calculated cruelty and the wife's desperate fight to trust her own mind.