The electors of a township in which a village is situated, and the electors of such village, may, if the electors of both so determine, unite in the enlargement, improvement, or erection of a public building.
For such purpose, an application shall be made to and filed with the board of township trustees, signed by not less than twenty-five resident freeholders of such township, who are not residents of the village, and an application shall also be made to and filed with the mayor of the village, signed by not less than twenty-five resident freeholders of the village.