Kyle Schmidt demonstrates a drill you can use for practicing “search and engage” techniques with multiple targets using a gun-mounted light.

I’d be very careful to note that this technique works best when searching for known hostile threats. You would use a different technique for searching your home using the spill from the light to identify friend or foe instead of aiming the gun directly at someone who could be a family member. Flashing the light against a white ceiling or light-colored carpet is much more preferable than pointing a gun at your spouse or child, and you’ll still generally have time to sidestep, then re-engage your light as you bring your sights and light online against anyone who needs to be shot.