Hi weekender01,
Unplug your trailer right now.
You may have what's called a "Hot Skin" problem where the trailer exterior components are carrying voltage. "Hot Skin" is extremely dangerous and you should proceed with great caution until you either are certain that's not the situation, or you get it fixed.
Not kidding. Unplug the trailer right now!
The next thing to do is to go to a hardware store and purchase a non-contact voltage tester. This will allow you to investigate without having to touch the thing that might be electrically hot. Get the $20 tester, not the $10 one.
Use the tester to determine what areas of the coach are carrying electrical current. Maybe it's just the screw, in which case Jerrod may be correct about the screw being in contact with a wire.
If it's more than that, you need to look for 2 separate problems that can combine to cause this problem. The first problem is that you have something leaking current to ground. The second problem is that the trailer is not correctly grounded.
Normally when you have something leaking current, the current flows to ground and is harmless. But if the ground is faulty, the current will find another path - sometimes through you to earth.
You can investigate the source of the current leak by turning all circuit breakers off. The "Hot Skin" should go away. Then turn breakers on one by one until the problem reappears. That will tell you which appliance is leaking current.
To find the ground problem, start with your 30 amp outlet and make sure it's wired correctly - especially if it's new.
A defective/damaged extension cord or 50-->30 adapter can have a bad ground.
Check the connection of shore power cord to the trailer to make sure it's seated correctly and no wires are loose.
Check the backside of the circuit breaker panel in the trailer to verify the shore power ground wire is not loose.
You can read more about "Hot Skin"
at this website.
If you're not comfortable investigating this yourself, get a licensed electrician to work on it for you.
And unplug your trailer until this is fixed!