You may at some time experience an electrical shock when entering or exiting your RV.
This is often caused by the wiring in the electrical receptacle that your RV is plugged into or an improperly wired extension cord. If the "hot" and "neutral" wires are reversed, your coach and you may become an electrical circuit with unpleasant or dangerous results.
There is a small polarity checker available that will eliminate the guesswork and the hazards before you plug in your electrical cord. Everyone should have one of these as standard equipment!
See: RV Shocking Article