Proceedings for the installation and maintenance of additional lights may be instituted by the governing body on its own initiative and shall be instituted by the governing body when:
(a) A written request therefor, signed by two members of the governing body, is filed with the governing body; or
(b) A petition therefor, signed by 20 or more taxpayers of the district, is filed with the governing body. The petition may consist of any number of separate instruments.