You are NOT at all (legally) free to arbitrarily turn off your ADSB on an aircraft equipped with it. 91.225(f) [1].
> Except as prohibited in [unmanned aircraft section], each person operating an aircraft equipped with ADS-B Out must operate this equipment in the transmit mode at all times unless [authorized by FAA or ATC].
A common way to add ADSB to an aircraft not originally equipped is replacing one of the lights with a uAvionics skyBeacon[2], which has a LED light + ADSB-out transmitter. So the nav light switch would control it, but you'd also now be required to have them on at all times.
> Except as prohibited in [unmanned aircraft section], each person operating an aircraft equipped with ADS-B Out must operate this equipment in the transmit mode at all times unless [authorized by FAA or ATC].
A common way to add ADSB to an aircraft not originally equipped is replacing one of the lights with a uAvionics skyBeacon[2], which has a LED light + ADSB-out transmitter. So the nav light switch would control it, but you'd also now be required to have them on at all times.
[1]: https://www.ecfr.gov/current/title-14/part-91/section-91.225...
[2]: https://uavionix.com/products/skybeacon/