Late reply: I think you misunderstood my comment. I was replying to:

> It definitely comes in at a higher voltage.

The voltage supplied to a US house is 120V RMS measured phase-to-ground. You will not find a higher voltage in your house. This does not mean that it’s appropriate to run any non-negligible current from phase to the ground (green / “equipment grounding conductor”) wires.

One can get vaguely close to an accurate understanding by imagining that there are four wires coming out of your main panel: +120V, -120V, 0V white (the “actually use me” wire) and 0V green (a safety wire where any current more than a few mA or maybe tens of mA depending on application is at least a mistake). There’s no 240V to be found.

This explanation falls apart pretty quickly — the US system is AC, not DC.