Ok, so I don't know all the cachers in the world - but I do know that as a kid, one of my favorite places to play (along with every other kid in the neighborhood) was on a large junction box in our suburban front yard.
Not once did any of us get electrocuted. There was the rare and unlucky squirril who would crawl in - you'd hear a big GAZUMP and the lights would go out for a few hours. Most of these ginormous boxes are now (mostly) animal proof - and I think that a set up like yours does not encourage the breaking in of the large...impossible to break into...junction box.
I say cache on! Clearly if the company was worried about the GAZUMP of humans, you would not have been given permission to place the cache. Liability is key here, my friends, and large companies want none of it.