We have 2 different ceramic style heaters in our camper we use when camping in colder weather. If plugged into electric shore power (and you've paid for your campsite), then you are saving YOUR propane to run the furnace by supplementing with electric heat (that you paid for with the campsite).
However, one thing you do need to mindful of. Your camper can only pull so many amps (either 30 or 50). In my camper, I've tripped the circuit breaker (inside the camper) when I turned (2 heaters) at the same time on the same circuit. And do not attempt to plug in an electric skillet too! You'll pop the breaker! No problem. Unplug something and reset the breaker.
But to answer your question: Yes! You can very comfortably run an electric heater in your camper. Just make sure you have somewhere safe to put it. We put one on the kitchen stove top. That spot is made for heat.
Second one sits on the bathroom floor facing our bed room (our bathroom has 2 access doors). This way they are not surrounded by something that could catch fire, and they have lots of air flow.