So, repairman jack is a character from a series known as the "Adversary Cycle", starting with a fairly well known horror book - The Keep.
The repairman jack series is somewhat pulpy, anti-hero (go figure), supernatural, detective story that is, on occasion, very violent and later books in the series have a strong horror element (as the story merges with the adversary cycle books).
The plot of the first novel -
Originally Posted by The Tomb
Amazon recommended it about a year ago. I finally bought it and read it while on a flight last xmas. When I arrived at my destination, I immediately bought the other 14 (!!!) and read them all by the time I returned home 2 weeks later.