Here was a surprise for me today. Luckily the HO had sprayed wasp killer in through the hole where they were going in/out and the 24VAC live was also going last year. Only about 10 wasps so I just shooed them away and skewered the nest out with a screwdriver. Most in the unit were dead from last year. Would've been a different story if the full nest was active!!!!!

afterwards I put insulation tape around the stat wire to plug the hole. In the first pic you can see the wasps congregating around the hole wondering what the heck just happened.