Under Tank Heaters?????

I wanted to add that I bought a 41qt tub that is made so bottom of it raised just slightly so that there is a gap between my shelf and bottom of the tub. I then used those little rubber feet (just like the once that come with a ZooMed heat mat) to get it just a tad higher. I put tin foil on the shelf and then the Ultratherm on the foil to direct the heat upwards (instead of taping it to the tub). The temp in the hotspot has been staying steady at 96 so far. I love that UltraTherm.

I was just wondering how anyone would go about setting up a thermostat in a wooden enclosure (not a rack)?

My plan is to have a wooden enclosure, with a UTH on one side (holes drilled in the wood for ventilation of excess heat), then the UTH covered with vinyl/glass/ceramic tiles or something... Where would I want the t-stat probe?