The real story of Winchester, the most haunted house in history.

For almost 41 years Sarah Winchester lived alone in one of the creepiest houses in the world.

Sarah was a widow. Her husband William Wirt Winchester, heir to the Winchester firearms fortune, passed away in 1881.

In the long, lonely years after his death, Sarah filled her time by adding extensions onto the home she bought in San Jose, California.

By the time of her own death in 1922, what started out as an eight-room farmhouse had been transformed into a sprawling 160 room mansion.

It spanned 24,000 square foot and was made up of a series of nonsensical add-ons – like doors and staircases that led to nowhere.

No one really knows why Sarah insisted on the constant construction on her house right up until her death. Until this day it largely remains a mystery.

One theory is that she wanted to relive happier times. Sarah and her late husband had built their former house together and some believe this was her way of trying to connect with him in the afterlife.

By constantly repeating an activity they enjoyed doing together, she was paying a secret homage to her late husband.

Another theory is that Sarah just wanted to keep all the carpenters who worked on the house employed. Apparently, she had carpenters working around the clock on rotating shifts and she paid them three times the amount they would have received elsewhere.

Others believe there was a more sinister motive behind it.

According to local legend, Sarah was acting on the advice of a medium who, while supposedly channelling Sarah's late husband, told her she needed to build enough rooms in the house for all of the souls who had been killed by Winchester rifles.

The psychic told Sarah she had to pay for all the people who had died so her family could make their fortune.

To add to the general spookiness, the home's misleading labyrinth of rooms within rooms, interior facing windows, doors that open to walls, and staircases that led nowhere, were all part of an elaborate plan to "confuse" the spirits of the dead.

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While we don't know what motivated Sarah, her story and the sprawling, mysterious mansion she left behind, have fascinated us for almost a century.

And now her story is being made into movie starring Helen Mirren.

The film, aptly named Winchester, will tell the tale of how Sarah paid the ultimate price for her fortune.

"There are many understandings of her," Mirren told the L.A. Times during an interview that took place in the house. "Was she a Rosicrucian? Was she a straight-down-the-line Christian? Was she haunted? Was she crazy?"

"If you have made a fortune out of death, you have to pay the price, a psychological price and a spiritual price," Mirren continued. "And I can only imagine that people who make fortunes to this day from selling armaments have pause at some point, especially if they are Christians: 'Am I going to pay?'"

The movie will also explore the otherworldly forces that could still be at play in the house to this day.

Winchester will be out in Australian cinemas in February.

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