Do you need a way to hide something of a bigger size, like bigger than would fit inside a hollow book? Here is another idea using books and a book case. This is only limited by the size of box you use and the number books you are willing to sacrifice to create the cover to the box. So let’s get started.
A sturdy cardboard (mine was a box that held dish washer tablets)
Books (enough to cover one side of the box)
Blue painters tape