7-5-2106. Control of conflict of interest. No member of the board must be directly or indirectly interested:

(1) in any property purchased for the use of the county;

(2) in any purchase or sale of property belonging to the county; or

(3) in any contract made by the board or other person on behalf of the county for the erection of public buildings, the opening or improvement of roads, the building of bridges, or the purchasing of supplies or for any other purpose.