Added a coal filter holder
Added a plug for the power port if not used
Added an accent piece that hides the gap because even without the pegs it would not fit completely
Removed pegs that didn't fit my fan

Print instructions

The fan holder should be printed with supports from the bottom. The plug and accent are optional.

Build instructions

Test if everything fits with your fan before fully assembling it. I needed to dremel parts of the fan frame away so that the switch would fit. I chose to glue the fan holder and the accent in after wiring and assembling everything.

I have used this switch but bridged it so that both sides turn the fan on: https://www.reichelt.de/miniatur-kippschalter-ein-aus-ein-3-a-250-v-goobay-10022-p285989.html