The Orphanage (2007) - DVD - used

Directed by J.A Garcia, who would go on to direct Jurassic World: Fallen Kingdom; this ghost story is easily one of our favorite horror movies of the last 20 years. The fact that Guillermo Del Toro was on hand as a Producer probably didn't hurt either. 

Per IMDB: "A woman brings her family back to her childhood home, which used to be an orphanage for handicapped children. Before long, her son starts to communicate with an invisible new friend."