Section 73. If in a city, except Boston, or town wherein elections are held by precincts, the city or town committee of either of the two leading political parties shall file with the aldermen or selectmen, at least two weeks prior to the time of holding its caucuses, a notice that such party desires to hold its caucuses by precincts, or by groups of precincts in any ward, the aldermen or selectmen shall furnish a polling place in each precinct or group of precincts for the use of such party, as provided in section ninety-three, and the caucuses of such party shall be held accordingly.