Section 71. Complaints as to quality and price of gas and electricity; investigation by commission; forms of complaints

Upon the complaint in
  writing of the mayor of a city, the trustees  of  a  village,  the  town
  board  of  a town or the chief executive officer or the legislative body
  of  a  county  in  which  a  person  or  corporation  is  authorized  to
  manufacture,  convey,  transport,  sell or supply gas or electricity for
  heat, light or power, or upon the complaint in writing of not less  than
  twenty-five  customers or purchasers of such gas or electricity, or upon
  the complaint in writing of the state consumer protection board, or upon
  a complaint of a gas corporation or electrical corporation supplying  or
  transmitting  said gas or electricity, as to the illuminating or heating
  power, purity or pressure or the rates, charges  or  classifications  of
  service of gas, the efficiency of the electric incandescent lamp supply,
  the  voltage  of  the  current supplied for light, heat or power, or the
  rates charged or classification  of  service  of  electricity  sold  and
  delivered  in  such municipality, the commission shall investigate as to
  the  cause  for  such  complaint.  When  such  complaint  is  made,  the
  commission  may,  by  its  agents, examiners and inspectors, inspect the
  works, system, plant, devices,  appliances  and  methods  used  by  such
  person  or corporation in manufacturing, transmitting and supplying such
  gas or electricity, and may examine or cause to be  examined  the  books
  and papers of such person, or corporation pertaining to the manufacture,
  sale,  transmitting  and  supplying of such gas or electricity. The form
  and contents of complaints made as provided in  this  section  shall  be
  prescribed  by  the  commission.  Such complaints shall be signed by the
  officers, or by the customers, purchasers or  subscribers  making  them,
  who  must  add  to their signatures their places of residence, by street
  and number, if any.