The Key Finder by Mary Beth Bowman

Tony Bagwell, a very normal young man with an unknown and strange past, is suddenly able to uncover all his mother’s secrets when a shining box, which holds only a key and a name flies through his bedroom window one night, sending him to a strange world where everyone knows him as the savior who will free them from the powerful and deceptive Spirits who have been possessing the land and the people.