I use JunWen LED kits that I purchase off of Amazon for the majority of basic lighting in a shadowbox or building. I suggest the Warm White version for starters. Each kit comes with a reel of 300 2835 LEDs. (LED size is defined in millimeters so 2835 means 2.8mm x 3.5mm). The strip may be cut every three LED's (see the small double copper-colored contacts spaced every 3 LEDs) and shorter strip may be connected to wires with the suitcase adapters shown. Orientation of +/- counts in the LED world, so if the light does not come on reverse the end that the suitcase connector is attached to. 10 suitcase adapters come in each pack. The LED kit comes with a 12V DC power source and dimmer. The LED strip has adhesive transfer tape on the back so it is peal and stick application. I usually adhere it to the ceiling.
Woodlands Scenics makes the Plug-n-Play system that has individual 5050 LED's on strands of wire that lug into their control modules. The control modules have dials that allow you to adjust the brightness.
I have also used SuperBrightLED 5050 LED's that come prewired with a 36" wire lead.
Squares in the pictures are two to the inch.
