I made a pair of coach lamps for my Buttercup that came out brilliantly. Hiding the wires, not so much. I did scratch in channels for the wires, but they still show. I didn"t make them deep enough. I did them with a caulk saw. It works pretty well if you don't have a Dremel with a router attachment.
I secured the wires with masking tape and they show through. They will certainly show through the wallpaper. I am thinking about facing the inside walls with card to help hide the wires. Has anyone else done this? What exactly did you do and how did it come out?