Ignoring the false equivalence of wasted candle light to stolen WiFi bandwidth, as has already been pointed out...

It’s an unspoken(?) assumption that one can’t apply for a remote job unless one has access to internet. Doesn’t matter whether it’s yours, stolen from a neighbor, or sipped from a coffee shop, so long as it’s reliable and of sufficient bandwidth. That’s the remote work deal.

Having the privilege to work remotely for a non-remote job requires the same deal, an your employer seems even less responsible for providing bandwidth in the latter case.