Notwithstanding the provisions of any special act to the contrary, no member of the board of education shall be employed for compensation by the board of which he or she is a member in any position in the school system. If any member of such board is employed contrary to the provisions of this section, the office to which he or she was elected or appointed shall become vacant. No provision of this section shall be construed to prohibit any member of a board of education from serving as a member of any school building committee established by a town or regional school district to undertake a school building project as defined in section 10-282.