(1) This act applies to townships and adjoining townships and incorporated villages and qualified cities. If reference is made in this act to townships, that reference applies to townships and incorporated villages and qualified cities. If reference is made in this act to township boards, that reference applies to township boards and the legislative bodies of incorporated villages and qualified cities. A township, incorporated village, or qualified city shall not use this act to lessen the number of paid full-time firefighters in that township, incorporated village, or qualified city.

    (2) As used in this act, "qualified city" means either of the following:

    (a) A city with a population of less than 15,500.

    (b) A city with a population of 15,500 or more if the question of raising money by special assessment and the amount of the special assessment to be levied annually under this act is approved by a majority of the electors in the special assessment district. The amount of the special assessment to be levied annually under this act that was approved under this subdivision must not be increased unless that increase is first approved by a majority of the electors in the special assessment district.