by Bohrium
I modified this staff model to make a light up version of it. Plus added some connector bits you can glue in between the long parts. Everything is glued together, except the top 2 pieces, which slide onto the battery/button holder and are kept there with a pressure fit.
I separated the crystal from the head, so I could print it in a different translucent filament. I had to pause the head print at about 75% through to glue the crystal in there. I printed the crystal at 100% infill to get more diffusion, but you can probably do thinner walls for it to be more translucent.
I designed the button holder for a specific random button I had lying around, so you may want to modify that to fit your needs. I also glued the battery holder onto the button holder, so you could insert it and pull it out of the shaft as one piece (the battery holder alone might be difficult to remove once you push it in there alone).
The button lid needs a really good fit to not fall out on it's own.
The battery holder is for 2x AA batteries, that should work with a regular battery spring and end contact bit. There's a notch on there for routing wires through without damaging them.
The electronics I used are super simple: 2x AA batteries, a toggle switch, a resistor and 3 LEDs in parallel.
Also check out the creator of the thing I remixed this from, he makes a bunch of other cool nerdy stuff.