How do you address an invitation to enlisted military wife and non-military husband?

When you address a letter to a person in the military, you address it by rank. Colonel John Smith. First Sgt. Joe S. Miller. There may be 10,000 men on the base. There will probably be only one Colonel John Smith, Likewise, with First Sgt. Joe S. Miller. The object is to get the invitation to the right person out of 10,000 some of whom will have identical names.