I recently had trouble with cats getting into the back of my pickup and tearing into the trash bags I have before I can dispose of them. I decided to hook up my spare electric fence charger, which puts out a pulse about every second. The bed of my truck has a plastic liner, so it's insulated. I have the charger grounded. I cut and laid in a section of galvanized fencing on the bed, and attached that to the charger. My question is, if a cat gets in there again, will they get a zap, or will it not work since they aren't then grounded. I used a fence tester, which has a small neon tube that lights up. I just connected it to the fence without grounding the tester, and it did light up slightly. So I'm thinking the cat may not need to be grounded. If anything, I don't think the cat would get the full charge because of not being grounded, which is fine. I just need enough to discourage it.