Click here to apply to become a substitute in the School District of Clayton!. District staff or those who have been selected to substitute teach in Clayton's. Hannibal Public Schools. 4650 McMasters. Hannibal, MO 63401. (573) 221-1258. [email protected] Substitute Teachers and Aides. (Kelly Educational. Thank you for your interest in working with Nixa Public Schools as a Substitute staff member. – Please choose the application located on the right side…