I designed this as a project for the K2 School of Contemporary Jewellery.
The KiCad files are in the attached repo. I recommend getting the boards made with a white solder mask and using 3mm blue LEDs.
After assembling the board, a hook needs to be made. The hook I made was a standard sterling silver brooch back that I soldered into the PCB holes. The hook acts as a switch- when it is closed, the LEDs light up.