Gotta give him credit for trying...
(In the States, I've seen people trying to inductively couple electricity from high tension distribution lines before. See here: https://skeptics.stackexchange.com/questions/23799/has-anyone-been-caught-using-inductive-coupling-to-steal-power or here: https://youtu.be/CLS8pbDNHbk)
they are trying to connect a transformer to a live power line?

Penny wise, pound foolish.
What’s wrong with tapping into free electricity?
Radio Shack had a simple kit to make an AM radio that picked up RF inductively to power it. Just a few parts and a few bucks. Nice little thing.
He must be a very bad miner, because even at today’s low bitcoin prices, 10000 Baht is still about 1% of 1 bitcoin.