Ayoob's advice is very situational. How many of us have family members who will bring someone else into the house - at night, in the dark - without the rest of the family being aware of it?** Any stranger in my house - particularly at night - is a HOME INVADER. Need I say more?
Other than my home, I don't see myself searching anywhere else at night. (I'm aware of the hazards of house clearing.) If something hinky is going on at night outside, the circumstance would have to be VERY unusual for me to go out there to try and sort things out solo - my plan is to call 911 and stay inside behind locked doors.
I agree that each person's own situation will adjust what you do. If someone enters my home unannounced day or night, but especially at night, they are a home invader to me too. While I'm not big on room clearing, my bedroom is on the first floor and the cops are a good 30 minutes out, so maybe I can hunker down, maybe I can't.
For outside, if I hear something, I'm usually investigating, because it's probably an animal, and I need to check, but it might not be, and I need to be prepared for two legs.
For my personal situation, I'm mostly for a light, and keeping my finger outside the trigger guard until I have a target, just as I do when doing defensive training at the range in daylight. I have the NODs option, which can mitigate the "gun flashlight", but as we have discussed elsewhere, NV comes with it's own pros and cons.