What exacty do you mean, "in your walls? I have a fair amount of experience building display cases. If you mean "in your walls"? It is a whole differentt meaning than "on" your walls. I can help if I have specificifics.
OsiaBoyce's entry looks like the opitimum, at this point I just say use K 5000 flourescent lamps and Sign Grade diffuser back plastic. Allow maximum distance between lamps and diffuser.
I built this simple display using old flourescent shop lights I had. It's got three separate 4' long lights screwed onto hinged doors behind the wall. It's not the nicest set up, but it was dirt cheap to build and works ok for me.
Here is the behing the scenes shot. The wooden panels have hinges that allow me to swing them down to change the bulbs. They are held up in place by a simple hook and eye. I have the lights plugged into outlets that are controlled by a wall switch inside the room.
Here it is opened up - I can lower them all the way down but when I did I couldn't get a good picture because of the glare. I know it's not a pro job but when I was building my basement lair I decided I would have a back lit set up, so that's what I came up with. I made a built in bookcase / tv / stereo / storage area and ran the long shelf on top with just enough room for the back lit display on top.
It looks kinda sparse right now because I have really gotten selective about what I keep after I dig it. Some years I have the shelf packed, it just keeps changing as I aquire and then as I dequire.....