Thanks for your responses.
I have put him in a playpen at naptime, but he screams the entire time and my two year old can't nap because he's so loud. He woke her up yesterday and today. I started off putting him in a bedroom with the door almost closed, then because of the screaming I put him downstairs in the dining room with the door closed, but he high pitch squeals and yells to the point he starts gagging and he's only left in there for 10 minutes before I check on him, but he just gets himself in such a mess.
I am going to give her notice to terminate the agreement.
I was worried I was being dramatic or unfair giving notice so soon after they started here, but you have assured me.