OP, Didn't you buy this bus six or eight weeks ago?
We know how this ends. 'Spilled' electricity does not puddle up, awaiting a mop.
diy the engine, plumb the water, hang sh!t tanks, work wood, seal glass, mend steel. All low risk projects. White fire can melt, burn and vaporize all of them.
Licensed Electricians know stuff.
Was the generator on fire? Or plugged into shore? Battery fire? Something odd.
"If there is no struggle, there is no progress."