YOu can make sequins that light up using SMT LEDs and crimp beads. With these you can make needlepoint (or other stitching) that lights up. I keep thinking of a lit lamp, spooky eyes, or a cool way to highlight a letter.
This YouTube video shows you how to do it.
The tutorial is done on cloth. To translate to to needlepoint, you are going to have to make some kind of solid backing for the battery pack so it won’t show on the front of the canvas. The backing should be against the canvas with the battery pack on top of it.. This way you will be able change the battery easily.
I would recommend doing the test circuit on a piece of scrap canvas and using a pen to mark the positive side of each sequin. I couldn’t find an easy source for the LEDs, so you’ll have to poke around to find them.
Thanks and a coolness plus award to Denise from Craft Gossip for finding this.