I would not sign it.
Do a search within EEOC or EPPA, you'll find that they can not include that in a requirement and/or for continued employment. With some exceptions of some government reqs.
Employee Polygraph Protection Act (EPPA)https://www.dol.gov/whd/polygraph/The EPPA prohibits most private employers from using lie detector tests, either for pre-employment screening or during the course of employment. Employers generally may not require or request any employee or job applicant to take a lie detector test, or discharge, discipline, or discriminate against an employee or job applicant for refusing to take a test or for exercising other rights under the Act........If you really want the job I would print the EPPA and show it to them that they are in violation, or don't sign it and show them that you have the right not to sign it, and/or report them. Someone needs to do it.