so a channel of a home receiver that puts out 8 ohms could power a 4 ohm sub?
It can do that without any wiring. Home receivers aren't affected as much as car amps when it comes to wiring ohms down too low. Try it out and see if the receiver gets too warm-if it does, it obviously won't work.
Better yet, just buy an 8ohm woofer for your home if you need a sub. Home woofers are pretty cheap.