The first person to use Edgar Allan Poe in a horror story was Manly Wade Wellman in "When It Was Moonlight" (Feb. 1940) in Unknown.  While Poe is doing research he uncovers a vampire and saves a man. I don't consider Poe in this story a ghostbreaker in the proper sense. It is  Marc Olden's Poe in Poe Must Die that qualifies here. Poe and his friends consciously seek out a sorcerer across two continents, facing magic and solving a mystery. The book won an Edgar for First Novel. The children's writer AVI would later write a straight mystery with EAP in The Man Who Was Poe (1989).