The film is adapted from a true story and written into a book by the novelist Andrea Perron. This story happened on the farm of Perron's family. The story sounds pretty clichéd, but when the whole incident is labeled with the words "real people and real things", everything is different. In fact, as early as 20 years ago, the film’s producer Tony De Rosa-Gullender got a tape of Warren’s interview with Perron’s family. At that time, the Perron family bought the house-of course, when they bought the house, they didn't know it was haunted. Back then, Tony dubbed all the tapes provided by Perron, and always wanted to put this story on the screen. At the end of the tape, Tony said: "If we can't put this story on the screen, I really can't imagine what we can do." In the same year, Tony negotiated with Perron and finalized the movie. However, this plan was repeatedly delayed.
After Tony studied the entire tape, he began to write the script. For fourteen years, he has been looking for opportunities to bring this movie to the screen. But most of the time, he returned without success. In 2009, Tony hired producer Peter Safran, and the two hired two new screenwriters to modify the script. The revised script was successfully sold to Xinxian Film Company. Although the film was bought by the new line at the end of 2009, it wasn't until 2011 that it finally started shooting. For this day, Tony waited for more than twenty years.
In the first half of 2011, James Wynn got the script of this movie. As the newest director of the horror world who filmed the "Chain Saw" series and "Latent", James Wynn admired this story very much. He feels that this movie just allows him to make an adjustment in the image style. He said: "At that time, I just finished filming "Latent" and got this script. After I watched it, I thought, oh my god, such a cool script is really rare. Of course, after filming so much horror After the film, I didn’t really want to shoot another story about supernatural, haunted, or exorcism. But the idea of directing a film adapted from a real story is still very exciting. Real story, truth The characters, real events, all of which made me pick up the guide tube of "Calling the Soul"."
