I need to know if there IS such a thing as "a Bradbury Box".

An author used the phrase: "I will have to put that idea in my Bradbury Box" and a relation of that person thought about having a box MADE to be the author's "Bradbury Box". However, we're not certain what context the original statement referred to, and whether it's a hypothetical 'box', virtual 'box', real 'box', or even a mental 'box', we are unsure. Can anyone help us? --Greyson