The writer who investigates haunted places in Stephen King's 1408 is Mike Enslin.
Mike Enslin is the protagonist of King's short story “1408,” first published in the 1999 collection Everything's Eventual. He writes books about supposedly haunted locations but considers himself a skeptic because he has never encountered convincing supernatural evidence.
Enslin checks into room 1408 at New York City's Dolphin Hotel despite warnings from the manager. The room's history and strange events challenge his confidence and turn a research assignment into a fight for survival.
The 2007 film adaptation, directed by Mikael Håfström, stars John Cusack as Mike Enslin and Samuel L. Jackson as the hotel manager. The film expands and changes aspects of the short story, so the character's name is shared while many plot details differ.