It’s a coincidence that memsaab reviewed Woh Kaun Thi? just after I’d seen Gaslight and decided to review it. The films are worlds apart (and yes, Raj Khosla fan though I am, I must acknowledge that George Cukor is better at this!) There is, however, an interesting similarity: a central character who seems to be steadily going insane.
That said, this is a great film, very watchable and with the beautiful Ingrid Bergman in a superb, Oscar-winning performance.