@Rylan25
So sorry this happened...
Was the high electricity bill due to the EV charger or were they doing crypto mining (bitcoin) with extra computer equipment?
We have had to add to our House Rules no crypto mining and excessive utility usage above the usual and customary will be charged to the guest. Some Hosts have had to add smart electrical monitors on their circuit breaker boxes so they can monitor electrical use through an app on their phone. We also add no EV charging for properties that don't have an EV charger.