What are some special duty assignments for a SSG that are not really common place?

The qualifications are fairly high and the application process is a pain but this turned out to be the best assignment of my 27 year career:

https://sites.google.com/site/armyattachemanagementdivision/home

Army Attache Management Division

Provide information regarding assignment to the Defense Attache System for U.S. Army personnel.

SSG Paga,

CID is not MOS dependent, although they do like you to have some type of LE or MP background it is not mandatory, in fact when there was a big push on about 5-10 years ago if you got accepted and while waiting for a school date/slot, they would OJT you with an MP unit for about 6 months and a current Agent for 6-12 months, the school dates on average would take 12-18 months to get while they completed your background, interviews, clearances, etc.

I did it for awhile when we were down from drug missions in the early to mid-90s, I enjoyed it, but I didn't like all the paperwork and office time, I was also still all gung-ho for the adrenaline action as well at that time, was still in my mid to late 20s.