I wanted to add more light to my bathroom, but did not want to get in the attic or cut a hole in my ceiling. This version screws to the ceiling and accommodates a 12" flush mount LED I got on Amazon.
I am not a licensed electrician. Copy my wiring at your own risk and only do what you are comfortable with. I cut the end off of a broken string of Christmas lights and wired that to the light. This allows me to plug the light into vent's internal outlet and the fan motor into the passthrough of the Christmas plug.
The only thing I don't like is that you can see the hole in the ceiling through the vents. I may put some screen material in there to help obscure the ceiling.
This is pretty large with a 290mm diameter. I have an Ender 3 Max and was able to print it in one go. I only used supports for the screw brackets.
I painted it with a dark satin paint. Between the paint and how high up it is, I didn't worry about sanding the print lines.