I'm not real impressed with a '3 mile' rated unit. Fencers are rated at what they stop having any effect on. Not worth getting anything less than 20-50 mile units. Those 3-mile units just aren't much.
Ground is very important. Bare ground wire, or grass on the ground wire, is _not_ a problem. You want it grounded. Only 2 foot ground rods is not good. I understand, you gotta work with what conditions you have, but burrying 6 or 8 foot grounds at an angle, or even flat as deep as possible, will give _much_ more surface for the ground to connect with the earth. With a weak 3-mile unit, ground is even more important.
You always want the ground connected to a good ground when using or testing the unit; with the ground unconnected, nothing will happen.
Touching the hot lead is up to you. I wouldn't. But then, I have the higher powered fencers. One time mom & I were walking the fence, pulling weeds. With a wooden handle, mom held the barbed wire electric away so I could reach the weed.... The handle slipped, a barb stuck me in the arm through the skin.
WOW. That tingled for a while. Skin is a pretty good insulator. Peircing the skin like that - wow.
With your test light, put the ground end on any good metal ground - like a metal T post. And touch the wire with the other end of the tester.
--->Paul