Here is some information I found on the web about the place
Gettysburg - Farnsworth House Inn - Considered by many to be one of the MOST haunted houses in America! The first house in Gettysburg to be investigated by renowned psychic Carol Kirkpatrick, as well as Ghost Hunters International, a crew from Pittsburgh, Chicago, and Southern California. The crews from "Sightings" (Sci-fi Channel), "Unsolved Mysteries", and The History Channel have done filming here. Mary, a spirit from the Civil War era walks the corridors of the Inn at night. There is also a civilian man carrying a child wrapped in a quilt. You can hear him sobbing in an upstairs room. A midwife is seen watching over a young woman in labor. Three Confederate sharpshooters remain at their posts in the garret of the house. A soldier carries a wounded comrade into the cellar of the house. His voice is heard singing to comfort his dying friend, who dies in the catacombs of the cellar. Cold spots have been detected. "Balls of white energy" were photographed as white "auras" of energy throughout the house. Guests report many strange happenings on their stays here!