Does the state of TN require married couples to each sign the loan documents of a refinanced mortgage?

It sounds like you are referring to community property states laws and Tennessee is not one. Those laws refer more to how property is divided when a divorce occurs. lenders require only the deeded owners of property to sign the loan documents. If the spouse who was married to the homeowner after the purchase was not added to the deed, then he or she will not have to sign any loan documents if the current owner refinances alone.