If you have it, you must use it. Switching off is not an option if its serviceable and compliant.
9B.5 If an aircraft in flight carries serviceable ADS-B transmitting equipment, the equipment must be operated:
(a) for equipment that complies with an approved equipment configuration set out in Appendix XI — continuously during the flight in all airspace and at all altitudes, unless the pilot is directed or approved otherwise by ATC; and
(b) for equipment that complies with the approved equipment configuration set out in Appendix XII, XIII, or XIV — continuously during the flight, within the airspace and within the altitude limits specified for the flight in the applicable Appendix, unless the pilot is directed or approved otherwise by ATC.