A simple tweak to the BentoBox V2.0 Activated Carbon Filter base that allows for the installation of a round toggle/rocker switch.
Here's the switch: https://www.amazon.com/dp/B0CPV5CTWX?psc=1&ref=ppx_yo2ov_dt_b_product_details

Bust out your angle cutters and snip the clips off of the side:

Clips

No Clips

After that just slide that bad boi in there.
There is an index piece on the side of the switch and a corresponding slot in the base so it's easy to see how it all goes together.
It's a decent friction fit but, you could put some hot or CA glue on there if you were worried about it.