How can I get rid of the huge wasp hive attached to my house?
Thank you for sending the picture to us at eXtension.
That hornets nest (most likely bald-faced hornet) has been there since May, when the first wasp, the future queen, started building it. It hasn't bothered anyone before now, and most likely, they will continue to not bother anyone who doesn't try to bother them. They won't become more aggressive, but they will defend the nest if anyone starts poking at it or throwing things at it.
However, knowing something that large is over your head can be extremely nerve-wracking, so I can understand if you want to remove it. The best way to do this (and ONLY if you have the ability to run QUICKLY) is to purchase an aerosol hornet spray...the kind that shoots a 10 to 20 foot stream of chemical. At dusk or very early in the morning, aim the chemical so that it sprays the bottom of the nest, where the entrance hole is. Saturate this area as best you can. This will often make the wasps rather hostile, so be prepared to run! Check on the nest from a distance later that day...if you still see wasps flying in and out of the nest, plan on hitting them again that evening/next morning.
Once you stop seeing hornets flying, knock down the nest and destroy it (stomp it, put it in the barbecue, whatever). There will be some larvae and pupae that may have escaped the chemical, and they will mature after a few days and start up rebuilding the nest.
Be careful, and good luck!