O.C.G.A. § 21-2-543.1

In extraordinary circumstances, where the Speaker of the House of Representatives in the United States Congress announces that there are more than 100 vacancies in the federal House of Representatives, the Governor shall issue, within five days after the speaker announces that such number of vacancies exists, a writ of election to the Secretary of State for a special election to fill any such vacancy from this state, which election shall be held on the date named in the writ, which shall not be more than 49 days after the speaker announces that such number of vacancies exists.