My daily RV Travel online magazine had this tip for the day. When I pulled into this park the switch was in the "on" position.
QUICK TIP
Important, easy, electric safety tip
Switch off the circuit breaker at the shore power before plugging in! When leaving, switch the circuit breaker off before unplugging. Just for fun, note the times that you pull into a campsite and the breaker is still on. That tells you that the previous occupant really didn't know what they were doing, was living dangerously, and had not read this tip!