The Haunted Bedroom (1919)

Betsy Thorne (Bennett) travels to investigate a missing man where she overhears a conversation between the sheriff and an imported detective that reporters are barred from the house and grounds where the mystery has taken place. She comes across a maid sent to the house from Richmond, and so frightens her that she gains a chance to act in her place. During the first night at the house she is terrified when she sees a ghostly figure come from the grand organ. The house is roused by her screams as she flees the room, and she is forbidden from going back there by the sister of the missing man. During the following night she is locked in her room during a thunderstorm, and while escaping through a window sees the ghostly figure again in the family graveyard. She makes an investigation which starts from a particular chord played at the grand organ. They find that certain keys cause a secret door in the organ to open, revealing a secret passage to a family tomb.