One of the things I usually travel with is a pair of jumper cables. For what it is worth, they have more uses than dead starting battery relief.
Case in point, the OP. As others have pointed out, if you get a shock touching your ladder or the shell or frame of your rig when plugged in, the campground power pedestal has a bad ground, and that is a dangerous condition. Until such time as you can convince management to fix the issue, running jumper cables from your rig's frame to some metal thing in the ground can at least minimize the risk. The hose bib works well for that, especially if the pipe into the ground is metal, but even if they used plastic pipe, the water column in the pipe is better than nothing.
I also would suggest having a VOM as well as one of those little yellow things suggested above. There are a lot of problems a VOM can diagnose that the yellow thing cannot. One of them is being able to SHOW the campground manager that the neutral wire isn't grounded at all, that the ground wire goes nowhere, or that the hot wire isn't.