The provisions of § 10-151 as it pertains to employment of certified professional employees of an incorporated or endowed high school or academy approved pursuant to § 10-34 and the provisions of § 10-153k shall not become effective until a majority of all the certified professional employees at such incorporated or endowed high school or academy elect to come under the provisions of said sections 10-151 and 10-153k. The election shall be conducted by secret ballot in September, 1979 and the results thereof certified to the Commissioner of Education.