Gonjiam: Haunted Asylum
곤지암 (original)
Starring Wi Ha-jun, Park Ji-hyun, Oh Ah-yeon, Moon Ye-won, Park Sung-hoon, Lee Seung-wook, Yoo Je-yoon, Park Chung-hee, Park Geun-hye
It's a mystery and horror movie, and has a rating of 6.4 out of 10 from Imdb which is usually fine for this kind of movie.
Watch it here
Not found streaming from Italy.