This is a camera lucida drawing aid to help project a ghost image on a piece of paper. I created this after looking into this area. You'll need to pick up a gooseneck clamp (or improvise).

You'll also need a 2"x2" mirror and a piece of glass to cut to fit at a 45 degree angle (~2.8"). You might also want a smaller square to cover the eyehole to avoid dust getting into the device. I used a hot glue gun to put it all together, and 3d print print the unit which has a screw hole on both sides (for right handed and left handed folks). The pictures show the general orientation of the glass pieces and the hot gluing. I've attached a diagram on usage off the internet.

I attached the Fusion 360 file in case folks want to remix or change anything. Enjoy!