Professional Editors in the Milwaukee Area...?

Why do you need an editor who is in Milwaukee? You're very unlikely to meet up with your editor and have long chats: all the work can be done (and usually is) by email or hard copy. Which means you have a much wider choice than you think you have when it comes to finding yourself a good editor.

(Don't pay anything to an editor until you've worked your way around the SYW sections here, though: you'll benefit a lot from SYW.)

The best place to find a highly qualified editor in the US is, in my opinion, through the Editorial Freelancers Association. You can post a job listing there for free; there is also a directory of members.

If the reason you want someone local is because you want some in-person coaching sessions in addition to the edit, I would encourage you to specify that in any job listings you create. Some freelance editors are very comfortable with that (I am, as a former teacher); others find that it's not something they enjoy or have skill with.

http://www.alisonedits.com/Alison_Janssen_Editorial_Services/Home.html

Alison is in the Wisconsin area, and I can vouch for her skills.