Unless you have a really big home with a lot of mining rigs you should not worry about taxes. You can say it is a server for a forex website or any other related excuse. Mining right now is not profitable although these latest updates I see in Nicehash with new miners are bringing good daily income in crypto not in Usd.
You can really make those kind of excuse if someone do check out your home (which is really very rare).If you are too honest then you would really just add up some headache on your own
Better to be quiet and just mine without caring or bothering yourself too much with that business code.