§ 208-a. School guards. The duly constituted authorities of any city, town, or village or any county police department or police district may designate, authorize and appoint such a number of persons as such authority shall deem necessary, and at such salaries as such authority shall deem advisable, as school crossing guards to aid in protecting school children going to and from school, and church crossing guards to aid in protecting persons going to and from places of worship, and for such purpose shall have power to control vehicular traffic within such municipality. A board of education or trustees of a school district may enter into an agreement with any city, town, village or county police department or police district whereby such school district pays for all or any portion of the salaries of the school crossing guards providing services pursuant to this section to the students of such district. Notwithstanding any agreement entered into pursuant to this section, school crossing guards shall not be considered employees of the school district. The authority of a board of education or trustees of a school district to enter into such agreement shall only exist when such agreement results in an increase to the number of school crossing guards employed by the city, town, village, county police department or police district.