I think 'loosely based' might work. Sort of. The house was originally owned by a Reverend Ketchum, who opened a mission to save First Nations people's via vivesection. (Hence the evil fridge magnets' instruction to 'katch em and kill em') After saving all the Dirty Injuns in the surrounding area, he cut his own throat so that his spirit would forever stay in the house. The movie is very obivously influenced by The Grudge, even down to how it looks.