See Familysearch for Sarah Couch Smith. Might be helpful.
The familysearch.org record to which Andrew linked says that Stephen Smith and Sarah Couch were married in Ridgefield, Fairfield County, Connecticut.
Connecticut Vital Records (The Barbour Collection), 1630-1870) has the following birth in Ridgefield:
Smith, Stephen, s. Samuel & Elizabeth, b. Sept. 23, [1714]
https://www.americanancestors.org/databases/connecticut-vital-records-the-barbour-collection-1630-1870/image/?rId=234617308&volumeId=13174&pageName=115&filterQuery=
Maybe that's him?
Update: Not sure it's him. He seems to have married a Deborah Spencer (1711-1812) in 1738.