Thanks for the info. But I should have said that I want to know how he was hired, who gave him his instructions regarding his duties, to whom he was reporting, etc.
Perhaps you could ask Dan Bongino. He's former USSS (and NYPD), has run for the House and Senate, and is now a talk show host. He has guest-hosted for Hannity and Levin. He probably knows Madison personally. I expect he would have an informed opinion as to how "normal" Madison's actions re Hillary were.
I do know that Madison has worked both halves of the Secret Service, both the protective and the investigative. You can find him quoted in articles about counterfeiting.
Here's his lengthy LinkedIn: https://www.linkedin.com/in/todd-madison-a43427129/
He joined the Secret Service in December 1993, having been a local cop in Pennsylvania for three years.