I have not connected this to Twine, but I have used this with my home automation system to detect the doorbell.
ELK-930
http://www.elkproducts.com/product-catalog/elk-930-doorbell-and-telephone-ring-detector
I agree this is what I was looking for as well. I will use mine in my wine storage and while I can use it to send me messages when the temperature is too high or too low. Getting the exact temp reported would be fantastic.