you can salvage peltier elements from those personal chillers that don't use compressor. or order online via aliexpress etc

then you could probably hook it up to an electronic thermostat module

take note peltiers are VERY INEFFICIENT i.e. to pump 100w from one side to the other you'll probably need 200w to do it, thus you'll need to deal with a total of 300w on the hot side. that is if you wanna run the TEC near its rated power. they're much more efficient at about half their rated power