The council of any city of the fourth or fifth class, or of any incorporated village, is hereby authorized to sell, transfer and convey at such price and upon such terms as said council shall deem advisable, any works, system or property owned by such city or village for the purpose of supplying such city or village and the inhabitants thereof with gas, electric or other lights, or any part of such works, system or property: Provided, That no such proposed sale, transfer and conveyance shall be valid until the same shall have been approved by the affirmative votes of 3/5 of the electors of such city or village voting thereon at a regular or special municipal or village election.