For the purposes of sections 7-324 to 7-329, inclusive, “district” means any fire district, sewer district, fire and sewer district, lighting district, village, beach or improvement association and any other district or association, except a school district, wholly within a town and having the power to make appropriations or to levy taxes. All districts established prior to May 29, 1957, under the provisions of the general statutes or by special act shall be continued; provided any such district may be dissolved or consolidated with the government of any town, city or borough of which it is a part in accordance with the provisions of the general statutes or may, by a two-thirds vote of those voters present at a district meeting, elect to be governed by the provisions of sections 7-324 to 7-329, inclusive, in lieu of the provisions of any general or special act under which such district was established or operated. Notwithstanding any of the provisions of sections 7-324 to 7-329, inclusive, a district established prior to May 29, 1957, and electing to be governed by said sections shall not be required to adopt the form of organization provided for in said sections but may continue its existing form of organization and nevertheless have and exercise the powers and duties granted to districts in said sections and in such event the officers of such district shall have and may exercise the powers and duties granted to district officers in said sections.