With a hollow form, especially if it has a small opening, what people see is only the outside of the piece - actually the light reflected off the outside surface. But with the availability of small battery powered LEDs, illuminating the INSIDE of a hollow form is relatively easy.
So here's an example of an internally lit, pierced lidded hollow form. First with just an LED shining up into the inside of the piece. Painting the inside of the piece white will increase the reflected light inside the piece.
But even with the inside surface painted white, the amount of light coming out of the pierced holes in the piece wasn't very bright Needed another way of gettijng light out of the piercings.
Solution: Insert a solid rod of acrylic up through the pedestal and put the LED under the bottom end?
Unfortunately, the light doesn't come out of the sides of the smooth, polished rod - and shows up only on the end of the rod.
Solution: Scratch the sides of the rod and it'll glow. So when you look in any hole in the sides of the piece - you'll see the glowing rod. Here's the idea.
Here are the actual parts - note the scuffed acrylic rod coming up out of the pedestal.
And here's t he piece - sans finial - assembled - with the internal LED light source Off, On but with ambient light and on with no external lighting. This one's tricky to photograph because the internal LED flashes on and off. Next time - no flashing - the LED will be On or Off.
NOTE: After patting myself on the back for coming up with the brilliant idea of internally lighting