Should anyone be looking for a real-life figure upon which to base a fictional occult detective, let me suggest the Reverend Richard Dodge (c. 1653-1746).
It seems that little is known about the actual man, but his reputation as an exorcist of malevolent spirits made him legendary. Literally. He’s become part of Cornish folklore.
The earliest reference to Dodge that I’ve found (so far) is in a work written by Thomas Bond and delightfully titled Topographical and Historical Sketches of the Boroughs of East and West Looe, in the Country of Cornwall; with an Account of the Natural and Artificial Curiosities and Picturesque Scenery of the Neighbourhood (1823). There, we read that Dodge was vicar of Talland — and, “by traditional accounts, a very singular man.” Though rumored to know a few things about the black arts, the parson apparently used this knowledge to expel unsavory spooks. Bond says that many of these spirits “were seen, in all sorts of shapes, flying and running before [Dodge], and he pursuing them, with his whip, in a most daring manner.” Before presenting the tombstone inscription of this whip-wielding, Cornish clerical cowboy who fought the Powers of Darkness, Bond says Dodge “was a worthy man, and much respected; but had his eccentricities.”