Very little of the filming took place in the actual mansion. The mansion's design in reality is extremely cramped, making filming very difficult. As such, most of the mansion's interior needed to be re-created on soundstages.
Sarah Winchester had severe, debilitating arthritis and had a series of short risers, only three or four inches high, in place of stairs, as it was very painful for her to raise her foot more than a few inches.
The 1906 earthquake happened in the early morning, around 5 a.m., not midnight. The top three stories of the house collapsed, and multiple rooms were shut up permanently at this time, as being unsafe.
The Winchester Mystery House is a mansion located in San Jose, California. It is believed to be haunted by the victims of the Winchester rifle. It has been a tourist attraction since 1923, a year after Sarah Winchester's death.
The real-life Winchester house has spider webs incorporated into its design, as Sarah believed that spider webs were good luck.