Did your CT ancestor serve in the First World War? Not sure of the unit?
The Connecticut State Library has digitized a book that can help. Called Service Records: Men and Women in the Armed Forces of the United States during World War, 1917-1920, it lists those who served by town. Entries are alphabetized by the individual’s last name, and include their full name, their mailing address (as of around 1941 when the book was published), and a description of their service.