I've seen (owned a house having) dual-fuel natural gas + electric light fixtures, mounted to walls, gas pipes to every room right alongside the (knob & tube) el

I've seen (owned a house having) dual-fuel natural gas + electric light fixtures, mounted to walls, gas pipes to every room right alongside the (knob & tube) electrical wires. So we've done weirder shit in the past to deliver two types of power throughout houses. And no, I never tried lighting one. Hopefully none of them had had an active gas supply in decades.