Use a ground fault breaker for that application if you do it in any fashion like you mention. Reduces the risk to the children.

Or give then something to do by installing 12 volt stuff and a battery charger somewhere for them to charge up some form of battery to power the low voltage system. Led forms of lighting for example will last quite a time on a small motorcycle or lawn tractor battery. Because of the acid risk I would make up a NiCad pack for recharging over an acid based battery.