In the year 2017, there is no reason not to have a light on your handgun. If you use your gun for home defense, it is critical to identify the threat and the backdrop. The easiest way to do that is with a weapon mounted light. You must also be careful not to point your gun at your family as you search.
PS: Keep your hand away from the muzzle as you manipulate the light.
Photo courtesy of Wicked Grips