That depends. Usually there is at least one light on amd I can tell if it is an intruder or one of the kids surprise visits. Full dark and no lights, I want to be sure who it is before I shoot.
Tactically. Understanding the original purpose of a light. Blinding light that's counter offensive. Disturbing the natural night vision of the human eye. Disorienting the other person. This tactic is also rather dated.
Like a camera flash.
It works well on seek and destroy. Defensive, I have a different opinion. The light itself identifies your position.
I'm sorry but when I hear a strange noise in the house I would like to see who is making that noise before I start shooting. It is not used for finding your way around the house but to identify your target. You can get lights that have pressure buttons on and off.
Streamlight TLR-1HP on the rifles and TLR-1 on the pistols. The HP is a bit of overkill in a house as it's a very focused beam (I can look out 300+ yards with it). The TLR-1HL or standard TLR-1 would probably be a better choice for in home use but the HP works pretty well too.
You don't shoot until you know what your shooting at. It could be a criminal, it could be your wife, or it could be little johnny getting a glass of water.
While I have a light on my G22, the only other person that should be in my house is the GF.
Looking down the hall from my bedroom will backlight anybody else, it will be dark behind me.
I agree with above statements, it's important to know what and who your aiming at. Now with that being said walking around in the dark clearing your house with a light on could make you a target. I personally run a TLR1 on my HD pistol.
Thats my sediment on lights and such is that it has to be momentary on and then click to stay on only. Some of the strobe stuff is ok but I don't deal with no high/low on my lights. I like the surefire scout but its too much to put on all my rifles. The tlr1s are nice, but I like the scout profile with a thorntail mount.