Mailed Warrant
Do you have an attorney? An attorney should be able to find out what is going on. Colorado has a public information web site called CoCourts.com. Do you know if Tennessee has anything like that. On the Colorado Courts pages, you can see if there is an outstanding warrant. It will show the case number and the charges, as well as the date the incident allegedly occurred and the date the warrant was issued.
It was nice that they mailed you the warrant rather than just locating you and arresting you. It must not be anything really serious. Might you have forgotten a court date on a traffic infraction or something? It could also be an error, but you should find out. I wouldn't just ignore it until they came looking for me.