Ok, think about this. If the probe moves away from the heat source the probe will read 80-70F depending on where it is, it won't get too hot, but the thermostat will work 10x as hard to heat up something that it thinks the probe is reading which will make it hot enough to burn your animal. Same thing if it gets spilled on. It will make the probe cold and make the thermostat crank up the heat because it thinks it's not warm enough. How can an alarm go off if the probe isn't on the thing that gets too hot or isn't reading the temps right because it's wet and cold?
Put the probe right on the ceramic heat emitter (which will read 100-105 probably, which is fine) but use a separate thermometer probe to read what it is in the enclosure so it doesn't get compromised.
You really should get some hides then. A piece of wood is not a good hide for a ball python.