I think folks are seduced by sexy TV dramas showing SWAT teams (as in 4-6 guys together!) rushing into rooms: but they are wearing armor head to toe, and already know the layout and have just stunned the bad guys with flash bang grenades. They are in full out "ID and shoot right now" mode. Totally different from a homeowner on his own!
I hated going into a building or house without a dog. Your right, if you use a light you have to be very careful, move slowly and only use the light when you have to.
Quick war story. Some rats broke into a guys house who died. I didn't have a dog and had to enter the house the way they did, by climbing through the front door. I found myself in the kitchen and took a couple steps forward. I looked to my right and there was a guy crouching next to the stove. If he had a gun he could have easily shot me. They were tearing out the copper plumbing in the basement.
The deceased homeowners .25 auto was laying on the living room floor. Glad they hadn't found it.
From my experience, I'd say move slowly, let your eyes adjust and listen. If you have to use a light maybe crouch down and hold the light up high, that way if the bad guy shoots he might shoot high, as I understand most people have a tendency to do.
If it's not imperative I wouldn't move at all until I was certain of the bad guys location, let him make the mistakes. Be careful when moving through hallways, stairwells etc. And don't get backlit by windows. You guys know all that.
A good dog is hard to beat. I have a .30 carbine that I can attach a bayonet to. :-)
The Marine Corps gave me an appreciation of bayonets.