I remember a demo where fluorescent tubes will glow, sometimes brightly, near high-power transmission lines

Goes back a long way:

https://commons.wikimedia.org/wiki/File:Nikola_Tesla_holding...

> The bulb is a prototype "fluorescent" light he invented consisting of a partially evacuated glass bulb with a single metal electrode. Nearby, probably behind the curtain, there is one of his Tesla coil high voltage oscillators which produces a radio frequency electric field. The electric field ionizes the gas in the bulb, causing it to glow similar to a neon light. This photo is a 2 second time exposure taken by the light of the bulb

https://collidecolludecollaborate.wordpress.com/2016/01/12/f...

https://www.bbc.co.uk/programmes/p00l1slw < although its not available at the moment

Yes. That should be done along hiking and biking trails under power lines. There's one in Silicon Valley along the bay shore line. The fluorescent tubes don't wear out; the filaments at the end are not in use. Just slip them inside polycarbonate tubes.