I won't say that's "ignorant" like my fellow keyboard warriors here. It's easy to pass judgment when you're sitting with your belly hanging over your boxers, bathed in the bluish light of your computer screen.
I could envision maybe the first ROUND in a magazine being a blank, but definitely not the whole magazine. That way if the perp's coming straight for you you could take two shots real fast and at least get him with one. Plus if your wife gets ahold of it after finding out you've been sleeping with the help, you can pretend her first (blank) shot did the trick.
But realistically probably not. I would have no qualms about killing a man (or woman!) I found in my house. At least that's what I think -- when the chips are down I might feel different.