I had another air filter with a barometer left over. Again I took all the filter things out of it to make room for a cable coming in on one of the intakes and I added the arm of a floor lamp on the top of the filter.
For this one I ordered a 12V warm white 1W LED and put it on a heatsink with thermal glue. The heatsink just fit into the round chassis on the end of the arm and is hold in place by a screw. This one has a external power supply.