Phobia

Phobia, also known by its original title of Alone, is a 2013 supernatural psychological horror drama film and the feature film directorial debut of Rory Douglas Abel. The movie had its world premiere on 3 November 2013 at the Drunken Zombie Film Festival and stars Michael Jefferson as an agoraphobic widower that begins to believe that he is being haunted by his wife's specter.

Synopsis from Wikipedia, CC BY-SA 4.0. Everything below written here.