This is a simple model that holds a 75mm lithophane, and clips to a generic nightlight. I found these nightlights at the grocery store, but I suspect any cheap nightlight with the same form factor will work.
This was designed based on a 75mm curved lithophane (3mm thickness) created on https://3dp.rocks/lithophane/. The fit is pretty tight and secure, but I also included a couple M3 screw holes in case it needs to be clamped in.
The author hasn't provided the model origin yet.