Sarah Avery 
The Ghost Puncher: A Short Story of Conjuration, Near-Instant Gratification, and Inside-The-Beltway Comeuppance [EPUB ebook] 
A Short Story of Conjuration, Near-Instant Gratification, and Inside-The-Beltway Comeuppance

You know the feeling: You learn about some appalling event in history that makes you just want to punch the perpetrator’s ghost. Well, there’s a professional who can help with that — at least, until new clients and targets pose dangers the ghost puncher never anticipated.