Killian- I don't think that anyone is advocating trying to clear your home just because you have a light. In some situations you may not have a choice but in general the "wait in ambush" mode is still considered your best bet. I don't have that option since I have a child in my home. I have to secure him if something is going on & take my armed wife with me in the process. Light good.
A light allows you to ID your target. People have shot friends, kids, spouses, neighbors, etc. due to lack of target ID. That would pretty well ruin your life. It also allows you to place more accurate fire on target than trying to line up Tritium sights on a dark semi-human looking blob on a dark background. Ambient lighting can help some- if there is any, but I doubt most homes are lit well enough at night to be able to positively ID the unknown contact in your home.
The in-home self defense laws vary widely from state to state so you better know them & be able to play along. If you live in a deadly force requires the threat of serious bodily injury or death state you better be able to articulate that you were so threatened. How can you do that if your target is dark on dark?
If weaponlights dodn't serve a useful purpose then why does every reputable trainer consider them to be a necessary piece of equipment? Why do the top level "shooting dangerous people for a living" folks use them?
People who sell tactical lights are *precisely* encouraging people to perform tactical sweeps. That's how they advertise the product. They show people doing tactical sweeps. There are probably some that have people who were involved in shooting incidents who will come on the commercial and talk about how the light saved their lives....but so far *I* haven't seen that. Probably will in the future now that I've said that.
People who shot friends, kids, etc...were too quick on the trigger IMO. Identifying your target is your responsibility before you shoot....always! If you aren't sure...better to let yourself get shot than risk shooting an innocent IMO.
Using lights to ID your target sounds fine...but why not perform a slightly different form of ID? How about you keep your tactical light off and whisper, hollar, or otherwise vocally ask, "Yo honey! That you?" Then wait. I call this method, "Tactical Enquiry". Actually...make that "Sniper Tactical Enquiry"...because when you put the word "sniper" in...it sounds cooler.
If whoever you are calling to doesn't respond, THEN you might entertain the idea of going to a light...but why a tactical light? Why not an overhead? If its your kid sneaking around to get a sodapop...then you didn't need the tactical light or the gun. If its a bad guy, then you didn't need to reveal your position while you sweep the entire room by having a light on your gun and being unable to see him.
I happened to watch Personal Defense TV today. They were addressing this exact issue. What struck me was how choreographed their moves were. You open the door, you see the guy in the corner. You shoot him. No one discussed what to do if the guy shot two times through the doorway when you opened it...and yet wasn't in your immediate line of sight. I think proper technique for this situation is to throw in a grenade, then everyone pile into the room after it goes off. But most homeowners won't have grenades. (Some of you do, and would use them, I know.) Imagine you are standing there having to make the decision. Two shots have just come thru the open door and you have no clue where from. Do you know how many people are in the dark room? You know at least one was! Do you know where they are? Do you know if others are now creeping toward you from other parts of the house cause they heard their buddy in trouble? No...you probably don't know. If you have practiced repeatedly to now push forward into the room...conditioned yourself to do that...then you may be stepping into some major event that could have otherwise been differently handled.
Bad guys shouldn't be expected to do the choreographed thing. They might decide if they are being hunted in the house to do the unexpected. Like turn on the natural gas if you are hunting them. They hear you in the next room... and they start the couch or lounge chair or curtains on fire. That will give their stalking homeowner something else to think about while they escape. (And if caught by the cops outside they can always say, "I was out jogging. I saw a fire. I rushed over to help. I kicked in the door but it was too much! God I hope everyone is okay!" Imagine doing your tactical sweep, opening the door and finding your sofa burning. You distracted yet? Put your own creativity to it and you can probably come up with a thousand and one ways that unexpected...non-scripted...things are going to occur which aren't covered in tactical shooting class. Then understand that more likely the people assaulting your home have got more info on YOU than you do on THEM. They've probably watched your place. They have an idea if its going to be just you and your wife as potential threats.
In my opinion...do a reallllllly unexpected thing yourself. Put in a loud speaker in each room. Something you can speak to every room or be heard in every room of the house. When you think someone is in your house, turn it on and say, "I've called the police. They are on the way." That's it. If they keep coming after you after that, then you have got beaucoup problems. Then you can use your tactical lights and sonic ears and...well Everything You Got!
As to your kid...yeah, that changes things. I'm not gonna deny that. But I'd suggest you put something like a deadbolt on his door that only he can open from the inside. And some sturdy doors.
I'm not saying doing tactical shooting courses aren't fun, or that they won't hone your shooting ability with quick decision making. I'm just saying be careful and don't fall into the mindset that because you HAVE taken one of these courses that it is going to play out that way in real life. It might...but more likely than not, it won't.