Back in the 50's I spent my military service as a radioman on an old diesel electric submarine. The radio shack is always off limits to the crew but there were always the sports nuts that knew when we copied the fleet broadcast and had the latest ball scores and they would come in the radio shack uninvited to check the scores. I hit upon an excellent deterrent by lifting my feet off the deck while sitting in my rubber bottom chair (insulating myself from ground), and grabbing the hot side of the 70 volt dc code key. All I had to do was turn around and touch the interloper and he would get the full shock because he would be the one grounded. That worked fine for the non-electronic trained guys but the crew members that were electronic trained quickly caught on and made sure not to touch anything that would ground them while in the radio shack. They in turn would carefully reach out into the passageway and touch someone else. If they were in turn touched ground then they would get the shock. I can remember once we had three guys lined up holding hands all the way out in the control room and everybody else avoiding them like the plague because if they touched them they would get shocked.

Those were the good old days. I'll bet if anyone tried something like that in today's Navy they would probably get put on report.