A few things to take into account:
1) You are woken from sleep, probably in P.J's and barefoot...BG is wide awake and maybe on "Uppers", adreniline surging, sensory perception on max, and he is dressed and his feet are shod.
2) He hears you coming, waits in ambush with the brass candlestick. You are the one walking making noise, he could be anywhere and is silent.
3) You are walking either from a lit hall or bedroom or are carrying your surefire, he is in the dark in a shadow.
4) You are alone, he is not. (BG isn't Robert Wagner and this isn't "it takes a thief).
5) You are sane....he is (take your pick, mix and match as you see fit): Psychotic, off his meds, zonked on LSD, just snorted big bowl of ice, Schitzophrenic, in a murderous rage, hears voices, .......etc
6) You yell "freeze", he instinctively swings around (from fright?) you shoot:- your sons/daughters friend who is sleeping over w/o permission and wanted a drink, your own image you see in the mirror (it has happened), your wife who couldn't sleep and was digging in the fridge, the plainclothes undercover cop dressed like a druggie because he was on his way to make a score but was the closest officer to respond to your wives desperate 911 "intruder on premises call" (you just killed a cop).
7) You yell freeze but don't hear his partner challenge you, "Man with Gun" he yells, as YOU instictively turn, YOU are shot. Real perp is long gone, luckily, you have so many good friends that are willing to take off time to personally comfort your grieving widow (betcha she looks real nice in black).
Ever see the movie "Hamburger Hill"? It usually takes no less than triple the advancing force to dislodge the defending force (some say 7 times the number). Ever hear of "D-Day"? It is estimated that 10,000 Allied troops died on the beaches, as opposed to between 4,000 - 9,000 Germans.
You obviously can't call the cops everytime the cat knocks something over, but if you are that jumpy (and maybe you're not), do things that will quiet your mind. Turn your day-house into a night fortress. PM me if you think I can be of service (this was my trade for a few years after a decade as a LEO).
If you are CERTAIN someone UNAUTHORIZED is in your home, herd the family in the "safe-room", (you should have one by now), barricade it, hunker down, you should have your sights on the door at ready, wife should be on the CELL phone speaking with 911 and NOT hanging up. Let her do the talking, explain that the family is in the safe room and the intruder(s) are roaming the house, that you are armed and that officers should not attempt to come through your door (more than one intruder/homeinvader has used the ruse "Police officer, open up"). I hope you will have more than a 9mm in your safe room, any .410/20/12 guage is your artillery (many laugh at a .410, there is no difference in power between a .410 and a 12 guage, and inside a house, I would venture they are extremely similar as the ranges are so short).
If you live alone (as I do), then the problem is less complex, you KNOW who is in your home and if they AUTHORIZED to be there. I have never been accussed of being a sissy, but I have a trunkload of fears that I carry with me from seeing what spews from the gutters after dark. I am touched for life, but don't get me wrong, I am not paranoid, what I fear DOES exist, and I have successfully confronted it time and time again. It took me ages to learn how to remove myself from the LEO mentality, but the best I have managed is to not stick my nose in other peoples business, but I never refused someone help. My point (I get off on a tangent too often), at night, my house is barricaded from within, entry points are hardened by effective yet inexpenssive and portable solutions by night, not seen by day. My windows are all locked (no bars though I would like to get some on the rear). A portable S&W motion sensor that covers all entry points but will not go off from the two dogs. (I hate the alarm and used it once, I let the dogs sleep with me and I know they will wake me...I already know they will not attack, but I know they will growl).
Curtains are drawn, shades down, no one needs to know where I am. Every room...............forget it, I am ranting again.
If you know BG is visiting, make him be the moving target, for all you know, he doesn't give a fig for the gold plated trophies, he may be after your scalp!