How do you help a child who is so afraid of Adolf Hitler's ghost that she won't leave her house?

She is 14 and she says that Adolf Hitler's ghost is in the city plumbing and she refuses to leave her house. When she is at home she keeps bricks and chains on the toilet seats and on the washing machine. She keeps all the sinks and bathtub drains plugged up and will only take baths not showers so she can keep the plug on the hole. She won't even use the hand shower because she thinks he could come out of it. She only drinks bottled water because she thinks tap water has Hitler in it. She went to four of the psychologists but it did not help. This is happening in Germany and no one wants to talk about it here.