Hi Gordon
Nutter has many different definitions here in the UK but I don't put you in that category
Radio frequencies are relatively scarce so they're licenced - not that everyone obeys, I remember years ago (back before mobile phones) when "farmers" cordless phones were sold here. A range of miles. Legal to buy and sell. Illegal to use, although I can't imagine any farmer just having one for decoration.
I've used Rife-like devices with frequencies listed by Hulda Clark and they've worked well.
I've also used NLP style spinning to get rid of pain. Well weird - a few puzzled people who were happy the pain had gone but didn't really understand how or why.
Lots of invisible things and - as you say - lots of things that are in theory restricted to "official" use. Or stuff like Pegasus spyware but that's another can of worms completely.
Fascinated to read more!
Trevor