jug: think this - guns don't need light to shoot, we do.... flashlights are only good if the power is out. If you need to grab a gun you will already know if you have power, and lights - a bad guys worst nightmare (er, lightmare???) - and you are home, turn on the darn lights - you know the layout of your home, he doesn't. A gun mounted flashlight makes you a target in a dark room with places for a bad guy to hide and both hinders and limits your visibility. If you need emergency light get one of those huge billion candlewatt hand-held white light night killer monsters, light up the whole room, blind his a.., ooops, eyeballs and steady yer aim son..........the rest is up to yew.........
Truth is that when you mount a rail to your gun you add weight and a night light also adds weight and this adds to fatigue and adds stress. You stick the thing as far out in front of you as you can to see better and you become the immediate target. Know the layout of the house and your light switches and get a monster light - might even weigh less than the light and rail mount set up......just a thought. Flashlights work in two ways - strong beam longer distance less peripheral light or weaker beam shorter distance greater peripheral light; shadows could be children, pets, visiting in-laws, bad guy(s), or your wife's old furniture that you never liked. Light it up, totally! You will see much better and that should help you, not he/she or them. Just a thought.