The wiki actually has pictures of this, but I've never thought about trying it myself until recently. I've made a few modifications of the idea. First, I put the cheese in maturation boxes. This allows it to control the humidity better and also have some thermal insulation from the cooler to even out the temp for the cheese. Second, I've put in a litre of water in a jar to act as a thermal ballast. Water has a fairly high specific heat. In other words it absorbs a fair amount of energy to raise the temperature. Finally, I put ice in a glass jar to keep the temperature down.
When ice is in water, the water will be at exactly 0 C. Melting ice takes energy and doesn't change the temperature. If there is some water in the jar with ice in it, it will equalise to 0 C pretty quickly and hold that temp. As the ice melts, it pulls energy from outside, which cools the outside. I can measure the temperature by measuring the temperature of the ballast water -- this will be a fairly good approximation of the temperature of the cheese. Having the maturation boxes ensures that there is an air gap (and plastic) between the cheese and the cooling jar and so cooling should be very slow -- allowing the ballast water to moderate the temperature.
So far it's working quite well. I make ice with my refrigerator and then add a bit of it in the jar in the morning. Over the day it takes the temp down to about 11 degrees and then overnight it warms up to 13. It's high maintenance (you need to fiddle with it every day), but for beginners who aren't sure if they want to spend a lot of money on a cheese making hobby, perhaps it's OK. I check my cheeses everyday anyway, so putting a scoop of ice in a jar is not a hassle. It needs you to be there mostly every day, though :-(
