Some things to think about:
1. What does the word actually represent?
2. What kind of box to underline the concept?
3. How to create the illusion of space perspective, colour, patterns...
4. How do you look at the message in the box?
5. Is it necessarily going to be a visual approach?
6. How does light enter the space?
First we "word-stormed" - here are a couple of the results -