Conn. Gen. Stat. § 9-460
If any party has nominated a candidate for office, or, on and after November 4, 1981, if a candidate has qualified to appear on any ballot by nominating petition under a reserved party designation, in accordance with the provisions of this chapter, and such nominee thereafter, but prior to forty-six days before the opening of the polls on the day of the election for which such nomination has been made, dies, withdraws such nominee's name or for any reason becomes disqualified to hold the office for which such nominee has been nominated, (1) such party or, on and after November 4, 1981, the party designation committee may make a nomination to fill such vacancy or provide for the making of such nomination as its rules prescribe, and (2) if another party that is qualified to nominate a candidate for such office does not have a nominee for such office, such party may also nominate a candidate for such office as its rules prescribe. No withdrawal, and no nomination to replace a candidate who has withdrawn, under this section shall be valid unless the candidate who has withdrawn has filed a letter of withdrawal signed by such candidate with the Secretary of the State in the case of a state or district office or the office of state senator or state representative from any district, or with the municipal clerk in the case of a municipal office other than state senator or state representative. A copy of such candidate's letter of withdrawal to the municipal clerk shall also be filed with the Secretary of the State. No nomination to fill a vacancy under this section shall be valid unless it is certified to the Secretary of the State in the case of a state or district office or the office of state senator or state representative from any district, or to the municipal clerk in the case of a municipal office other than state senator or state representative, by the organization or committee making such nomination, at least forty-two days before the opening of the polls on the day of the election, except as otherwise provided by this section. If a nominee dies within forty-six days before the election, but prior to twenty-four hours before the commencement of the period of early voting at the election for which such nomination has been made, the vacancy may be filled in the manner prescribed in this section by two o'clock p.m. of the day before the first day of such period of early voting with the municipal clerk or the Secretary of the State, as the case may be. If a nominee dies within twenty-four hours before the commencement of the period of early voting at the election and prior to the close of the polls on the day of the election for which such nomination has been made, such nominee shall not be replaced and the votes cast for such nominee shall be canvassed and counted, and if such nominee receives a plurality of the votes cast, a vacancy shall exist in the office for which the nomination was made. The vacancy shall then be filled in a manner prescribed by law. A copy of such certification to the municipal clerk shall also be filed with the Secretary of the State. Such nomination to fill a vacancy due to death or disqualification shall include a statement setting forth the reason for such vacancy. If at the time such nomination is certified to the Secretary of the State or to the municipal clerk, as the case may be, the ballots have already been printed, the Secretary of the State shall direct the municipal clerk in each municipality affected to (A) have the ballots reprinted with the nomination thus made included thereon, (B) cause printed stickers to be affixed to the ballots so that the name of any candidate who has died is deleted and the name of any candidate chosen to fill such vacancy appears in the same position as that in which the vacated candidacy appeared, or (C) if the vacancy is not filled, cause the name of the candidate whose candidacy has been vacated to be obscured in such manner that such name is no longer visible.
Conn. Gen. Stat. § 9-460
(1953, S. 617d, 618d; November, 1955, S. N109; 1957, P.A. 518, S. 38; 1958 Rev., S. 9-132; 1963, P.A. 17, S. 83; P.A. 81-447, S. 15; P.A. 82-247, S. 11; P.A. 83-475, S. 35, 43; P.A. 94-203 , S. 6 , 12 ; P.A. 03-216 , S. 1 ; P.A. 07-194 , S. 13 .)