Whenever any mosquito abatement district owns any personal property which in the opinion of three-fourths of the members of the board of trustees is no longer necessary or useful to, or for the best interests of the district, such a majority of the board of trustees then holding office, at any regular meeting or at any special meeting called for that purpose, by ordinance may authorize the sale of that personal property in such manner as they may designate, with or without advertising the sale.