I have made some led strips to provide an eerie green illumination within the coffin as the lid opens. They are strips of 9mm plywood with five 10000mcd 10mm LEDs attached. I've split them into two parts to allow them to be fitted along the edges of the coffin.
Here is a picture of the LEDs illuminated:
And a close up:
The LEDs will be illuminated as the lid starts to open, and turned off when it has closed.