I bought black framed shadow boxes from Michaels, (12×12) I think but the actual dimensions are slightly larger. I added self adhesive LED light strings along the inside edge and attached the lights to a battery box. Battery box is attached to frame with double sided tape for easy access to the switch and the batteries. I also used black masking tape along the edge of the glass and transparency to soften the edges.
Pictures attached but they look much better in person.