Conn. Gen. Stat. § 9-224b
Registration as write-in candidate in special election to fill vacancy.
(b) In order to be a valid write-in candidate in a special election called to fill a vacancy in the municipal office of town meeting member in any town having a representative town meeting which has seventy-five or more members, a person shall register with the town clerk of such town not earlier than ninety days preceding such election and not later than the last business day preceding the commencement of the period of early voting at the election.
(c) Any such registration shall include a statement of the office sought by such person and a statement of consent to being a write-in candidate by such person. Such registration shall not include a designation of a political party.