In addition to the conditions and limitations imposed by § 182 of this article, any such proposed sale, lease, exchange or other disposition of any municipally owned electric plant and/or gas plant, as defined and contemplated by said section, shall also be ratified by the affirmative vote of a majority of such persons, residing within the corporate limits of such municipal corporation and eligible to vote at the last preceding regular election therein for municipal officers, who shall cast ballots at a special election for that purpose, to be arranged for and held at such time and place within such municipal corporation and in such manner as such municipal corporation shall prescribe, provided and on condition that a written petition to such municipal corporation requesting it to arrange for and hold such special election for such ratification or disapproval of any such sale, lease, exchange or other disposition, shall be signed by at least ten percent of the voters in such municipal corporation, qualified as aforesaid in this section, and shall be delivered to said municipal corporation within thirty days after the date of publication of the second notice required by § 182; and if any such sale, lease, exchange or other disposition shall be ratified as aforesaid at such special election, then such municipal corporation shall forthwith execute all transfers or other title papers necessary to consummate and effectuate any such sale, lease, exchange or other disposition. But if no such petition for a special election be signed and delivered to said municipal corporation, as aforesaid, within the said period of thirty days after the date of publication of the second notice required by said § 182, as aforesaid, then ratification of any such proposed sale, lease, exchange or other disposition by said voters, as heretofore authorized in this section, shall not be required and no such special election for that purpose shall be held, and any such municipal corporation shall forthwith execute all transfers or other title papers necessary to consummate and effectuate any such sale, lease, exchange or other disposition, and any such sale, lease, or other disposition shall be as valid and effective as though the same had been actually ratified by the said voters at a special election petitioned for and held as herein authorized; and provided further, that nothing contained in said § 182 or in this section shall in any way be construed to qualify, limit or abridge the power and authority, now or hereafter conferred upon any such municipal corporation by its charter or by special act of the General Assembly, to sell, lease, exchange or otherwise dispose of any such electric plant and/or gas plant, or to qualify, limit or abridge the manner of exercise of such power and authority as prescribed in any such charter or special act, and provided further, that nothing contained in § 182 or in this section shall apply to Washington County, Talbot County, or the municipalities of Centreville, Snow Hill, Rock Hall, Hagerstown and Berlin.