I have a safe in the wall behind a permanent bookshelf in a random room of my house. One has to remove several shelves and a false back to get at it. A safe is

I have a safe in the wall behind a permanent bookshelf in a random room of my house. One has to remove several shelves and a false back to get at it. A safe is best hidden - otherwise seeing it is an incentive to rob you. My children don't know it exists.