From the Tennessee Department of Environment & Conservation -- Tennessee Radon Program:

https://tdec.tn.gov/Radon_Online/frmRADON_Online.aspx

Fill out and submit the form to receive a Radon Test Kit (laboratory analysis included). This test is easy to perform and the results will be sent directly to you. Only one kit allowed per household. WHILE SUPPLIES LAST! Please allow 6-8 weeks to receive a test kit. Due to interest and high demand, receipt of kits may be delayed.