[4RE KLR]

Josh,
If you take off one of the electrical plates the old wiring will be in separate strands as opposed to being romex. Romex is the wire that would have all the wires inside an insulator wire. For example, a white one a black one and a bare copper one. (for 115)

The old wire will have two probably not three wires. The third wire would be the ground. In the old homes the ground wire was not always run to each opening as it is today.

You can also look in the attic if you can get to it for the same thing. You can also remove the ceiling fixture and look there as well. I would know for sure before you put the insulation on top of it as I have seen this cause fires just as you have been warned, it does happen! Yes it would depend on the condition of the wire but are you willing to take that chance. Me neither.

If the home was built back then there are many ways you can help with the energy loss you are experiencing. The first is insulate where you can, the second is the windows. If you can upgrade the windows do so. If you can't make sure they are sealed all the way around them inside and outside. I have had people tell me they have caulked the windows and when I went out to look I could almost put my hand from the outside to the inside of the house. Look under the window seals for openings, look on top of the windows. Basically if it is hard to get to, that is exactly where it will need the most caulking.

If you can't insulate the house or that room, go to the hardware store and by wall plate insulation pieces. They are usually grey in color and are easy to install. Just take off the switch or plug plate put these insulation pieces on and then put the covers back on. You will be surprised how much that helps. THis will stop the drafing in the rooms.

Also cover the windows. If you do not have curtains or drapes get them. They block the sun out in the summer and keep the heat from coming in as well as contain the energy loos to the area between the drapes and the windows in the winter. This will slow down the draft loss considerably.

If it is a pier and beam house be sure to cover the vent openings on the perimeter of the house during the winter and open them in the summer.

Also if it is a pier and beam house you can insulate the floor. Have the insulator go under the house and hang the installation on the bottom side of the floor. This will do wonders for the inside temperature of the home.

If the AC units are not new I would look at how old they are and how efficient they are. Get the highest SEER rated units you can afford. You will not regret it.

I have been in the construction business for 23 years and have remodeled many old homes like yours. It is not hard to control the weather inside the house if you put your mind to it.