Arthur's BirdFeeders & BirdHouses

In the winter we went to a garage sale where i bought a small, plain little cardinal birdhouse for a quarter. I painted it with small roses and the door hole with a green rim, sealed the outside, and when spring arrived, I hung it in the tree in our backyard. We have a pair of cardinals in our tree, but not the birdhouse, they sit on the feeder and sometimes the little stopper for them to stand on in front of the house, but they never went inside. Just yesterday, I got really frustrated and went out to look at the house because I wanted to know why the beautiful red birds are so repulsed. Inside, i found a wasp nest, and a fat queen laying eggs inside. I have a terrible fear of flying stingers, and taking the birdhouse apart is not an option. How can I take them out, kill them, and keep them out for good without taking the birdhouse apart and repulsing birds?
I'm looking for serious answers.