Whenever one-fifth of the registered property taxpayers of any parish or municipality petition the governing authority to levy a special tax on all taxable property of the sub-division for the purchase and improvement of grounds and for premium awards for municipal, district, and parish fairs, the governing authority shall order a special election for the purpose.  The election shall be held under the general election laws and at the polling places at which the last preceding general election was held, not sooner than thirty days after the official publication of the petition and ordinance ordering the election.