Is adding urine to flour a mental illness?

Somewhere there was news of urine being found in a juice shop. And somewhere there was news of spitting in a tandoor. Many such incidents came in front of you. Which shocked you. You were forced to think how can someone do this. But can you ever imagine whether someone is doing this in your house too. Is he mixing dirty things like urine in your food. Because a shocking incident came to light in Ghaziabad, UP. Which has shocked everyone. Where a maid was cooking food by mixing urine in flour.