The Mathias Ham House in Dubuque, Iowa, is considered haunted due to multiple deaths and tragic events within the home, including the killing of an intruder by Sarah Ham, Mathias's daughter. Visitors and staff report paranormal phenomena such as phantom footsteps, cold spots, and the sound of a non-functional organ. Some experiences also include the sound of doors opening and closing and a shadowy figure seen in the parlor, which is believed to be Mathias Ham himself. Visitors and staff have reported hearing phantom footsteps, doors opening and closing, and the sound of an organ playing. A shadowy figure is sometimes seen in the parlor, and visitors have claimed to see a woman in white, believed to be Sarah Ham. Cold spots and strange smells, like roses, have been reported by visitors and ghost hunters. Ghost hunting teams have even recorded ghostly voices, with one instance of a woman's voice asking "Who's there?". The house is associated with multiple deaths, including Mathias Ham, his first wife, and their daughter May. The most well-known incident involves Mathias's daughter, Sarah, who shot and killed an intruder inside the house. These past events are believed by many to be the source of the lingering paranormal activity within the home. The Mathias Ham House is now a museum operated by the Dubuque County Historical Society.