IKEA items used: Böja standing lamp
Simply disassembled the original Böja standing lamp, removed the switch, lengthened the cable, and reassembled it to be used upside down. The fitting for the lamp can also be used to hold the lamp shell while upside down. Fixed the base to the ceiling by screwing it to a wooden bit under the stand where the weight was before, which I first fixed to the ceiling.

~ Wouter