The resolution of the board of supervisors shall contain a proviso that it shall not become effective or binding upon the county until it shall be approved by a majority of the electors voting at an election to be designated. The board of supervisors may submit the question of the issue and sale of said bonds at any regular election held under the general laws of the state of Michigan at which the electors of the entire county vote, or it may designate a special election to be called by the county clerk by direction of said board of supervisors for the purpose of submitting to the electors the question of issuing said bonds. The board of supervisors may call a special election for the purposes of this act upon a date coincident with any local or municipal election or primary election for any portion of the county.