We have lights with newer electronic ballasts and some with the old magnetic ballasts. If you take the tracer part of https://www.amazon.com//dp/B0042VII7A/ you have to be within a few inches to pick up the electronic ballasts. You can pickup the magnetic ones from 10-20 feet away.
(We have the LED's to replace them but finding times to do so is a problem.)
It's usually electronic ballasts that cause more interference since they have an oscillator that runs in the high kHz/MHz, while the magnetic ones don't oscillate at more than the 50/60Hz mains frequency.
(We have the LED's to replace them but finding times to do so is a problem.)