electical safety

The first step in electrical safety is isolation but sometimes that can be a danger. I was repairing an air con unit a while ago and went to turn off the 25A breaker .I had propped  open the metal   meter box lid so was not touching anything and when to turn off the breaker and copped an electric shock. The shock was not a serious one, I did not get hooked up,  just a good boot. What had happened was the building was right on the beach and the salt air had entered the meter box and encrusted the breaker allowing power to track from the active screw to the surface of the breaker it also had been raining the days before. In the picture the black lead is to earth and the red is onto the plastic body of the breaker.