No member of the General Assembly or member of his immediate family shall be elected to the commission while the member is serving in the General Assembly; nor shall a member of the General Assembly or a member of his immediate family be elected to the Public Service Commission for a period of four years after the member either:
(1) ceases to be a member of the General Assembly; or
(2) fails to file for election to the General Assembly in accordance with Section 7-11-15.