The Winchester Mystery House was built in San Jose by Sarah Winchester, the widow of Will Winchester (who worked in her father-in-law Oliver Winchester's gun business). Sarah inherited a fortune from the gun manufacturing company run by the men in her family. She was convinced after her husband's death by an occultist that the spirits of people killed by her husband's guns were trying to get to her, and that the only way to keep them at bay was to continually have work done on her house. This sounds like a completely fictional story, we know, but it's not.
It is, however, being turned into a movie starring Helen Mirren, because it's just that good:
The Smithsonian reports that Sarah paid 16 carpenters to work on her house in shifts, and they were paid three times the going rate. The work went on 24 hours a day from 1886 until Sarah died in 1922.
The Winchester house is open to public viewing via tours. Many stairs, doors and windows lead to nowhere. There is an estimated 200 rooms, 10,000 windows, 47 fireplaces, and 2,000 doors, plus trap doors and spy holes, if it weren't freaky enough. Lots of people who visit claim they feel a ghostly presence inside.
Sarah Winchester built a house in maze form to confuse ghost. Doors that lead to now where an you have to have a guided tour— Whiterabbit (@mcferrin000) October 21, 2017
No one is entirely sure why Sarah believed so firmly that building was the only way to escape the vengeful spirits she thought were punishing her for making a fortune off guns. Maybe she was building them a place to live, maybe she was trying to elude them. One thing is known, however: she had a very cute dog.