A good grounding in electricity is very beneficial. Take a look at one of the "household" type encyclopedias, it will explain the main ideas.
Also an old trick from the broadcasting industry: If you think some object might have errant electricity running around in just waiting for you to come along and serve as a path to ground, brush it with the BACK of your hand. That way, if there is some juice, your muscles will pull your arm back out of harm's way. Reaching out with an open hand in the normal manner can trap you if your fingers contract around whatever you touched. When ever I approach the old 'Silver Pullit' I brush the back of my hand against the trailer skin which reassures me that it is OK to grab the handle next to the door when I enter. It is a habit that also serves to remind me that electrical problems can occur, especially in campgrounds.