The idea for the film’s story comes from Jeff Howard, who penned episodes of Netflix’s The Haunting of Hill House, and Mike Flanagan, the writer and director behind the upcoming sequel to The Shining, Doctor Sleep. Howard wrote the script alongside Alexandre Aja and Nick Simon, who wrote The Girl in the Photographs.
Article source: https://www.cinemablend.com/news/2478194/crawl-director-making-a-choose-your-own-adventure-haunted-house-movie