Not to nit pick but if you ever have more than a few volts between earth and neutral you have some serious problem with your house wiring.
Back to the deck, imagine kids are playing and the barrier breaks and one of the kids falls and become paraplegic... Just as bad no ?
What I'm getting at is that there seems to be all this hocus pocus don't touch or you will probably die around electricity (and plumbing to a point) when in fact it's not more dangerous than many other activities we just do without thinking.
Look at the sharp/dangerous (jointer, shaper comes to mind) woodworking tools we have in our sheds, a child could turn a power tool on cut a big chunk of flesh out and bleed to death.. It's a stretch but not impossible.
Now imagine if there was a powerful woodworking union, that lobbied the gvt so all woodworking equipment could only be installed/used in registered business presimses by qualified people...
Nic