Castle defense or not, you have to protect your family. I agree with doing all you can so the bad guy picks a easier targert (motion lights, security system and a good dog). I have all of those. With that expressed if a bad guy comes into my house I'm not going to announce that I'm armed (then he/they will know where I am). My home is fair sized and all on one floor. My son's and daughter's rooms are before mine so a threat would be in there rooms before mine. So I'm going to the threat, I might have a bit more experience but even with little training the goal is the same. Identify the threat and remove it.
I stress on identifing the threat...know for certain that isn't someone that should be in you house and with your firearm aimed at center mass ask once for them to get down or you will fire, if they do anything less than that then fire. After, all you say to LEO is you shot an intruder and you need legal councile before you say more.