Vacation Scammers
Scammers love to prey on people’s fears to get what they want. If you’re not smart about it, they will make you believe that if you don’t do, as they say, you’re going to end up in trouble. The OP was away on vacation while his sister was house-sitting for him.
She received a call from someone who told her that the OP was going to be arrested the next day for an undisclosed charge unless she paid $900 for the case to be dismissed. She tried to call the OP but he wouldn’t answer since he was on vacation. So, she did what any good sister would do- she used his card to pay the $900.