Carnacki

The detective of the occult and supernatural
The stories are influenced by the tradition of fictional detectives such as Sherlock Holmes and like Holmes Carnacki lives in a bachelor flat in No 427 Cheyne Walk, Chelsea; and the stories are told from a first-person perspective by Dodgson, a member of Carnacki's "strictly limited circle of friends" (much like Watson). But where the Holmes stories never made use of the supernatural except as something to be debunked, this is the central theme of the Carnacki stories, though several of the stories do have non-supernatural endings.
The character of Carnacki was inspired in part by Sheridan le Fanu's Dr Hesselius, a supernaturally inclined scientist and is also highly reminiscent of Algernon Blackwood's John Silence (both available in the yellowbacks revival).