I don't think the breaker is really relevant here. Unless you've been impaled by a spike, it's impossible to draw 15A of current through your body from a 120V o

I don't think the breaker is really relevant here. Unless you've been impaled by a spike, it's impossible to draw 15A of current through your body from a 120V or 240V circuit. At those voltages, there's really no difference (to you) between shocks from circuits with or without a 15A breaker. I guess there is a asterisk here if you're also shorting something much more conductive than yourself, since the breaker might cut power before you'd naturally let go and break yourself from the circuit. But that seems like a pretty unlikely situation for most home shocks.