Rewiring old houses is not just a skill — it’s an art. You have to be part electrician, part carpenter, part plasterer, and part magician. And like most magic, it’s all an illusion. We can’t always get wires to where we need them without disturbing the existing walls. The trick is knowing how to make it look like we weren’t there. I was lucky enough to apprentice under an expert rewirer. He taught me not only electrical contracting but a little about all of the trades.This knowledge has served me well when working in old houses.

Have a Plan

When rewiring a typical house, I’ll wire the first floor by working up from the cellar, then run a few feeds up to the attic and wire the second floor by working down from there. Planning is at least half the battle. Try to coordinate with other remodeling crews working in the house at the same time. If the plumber has to open a wall anyway, you may as well run your wires before it’s closed up again.

Pulling Wires

To snake wires from one part of the house to another, I use 1/8-inch-wide metal fish tape. It’s stiff enough that I can shove it through some obstructions (like plaster buildup) and flexible enough to detour around others (such as blocking and cleats).·It’s usually easiest to pull the wires through the wall cavity in the same direction that you fed the snake in. Since snakes come in 50- or 100-foot lengths, I often cut them shorter to avoid having to pull all of it up on a shorter pull. I recommend getting the longest snaking jobs done first in case you have to cut the snake shorter for another pull. I store my snakes coiled up, so I have to straighten them before I start work. If the snake is still coiled, it will coil up inside the wall cavity. On each end of the snake I bend a hook approximately 1 inch long and about 1/4 inch across. To attach three-wire Romex to a snake, cut through two of the wires at a 45-degree angle about 5 inches from the end (see Figure 1).

Figure 1. When attaching Romex to a snake for a long pull, the author makes a strong, twisted loop, as shown, and wraps the whole connection in electrical tape.

Bend the third wire through the hook on the end of the snake. Tape everything shut to avoid snagging inside the wall. If a pull is long or there is likely to be a lot of friction to fight, twist the wire around itself a few times before you tape it.

String.

In straight chases or in balloon-framed buildings, it’s often easiest to use a string and a slim weight. I can usually get the string to the bottom with just a couple of shakes. In difficult areas, it’s a good idea to pull an extra string when you pull the wires — you may need it later.

Snake Grabber

With a little patience and finesse, one person with a "snake grabber" can do some of those difficult snaking jobs that usually take two people. This is a tool that I make from BX cable, aircraft cable, and a short length of fish tape (Figure 2).

Figure 2. The author’s homemade "snake grabber" uses aircraft cable inside a stud bay to help hook a snake that is probing the wall.

To use the snake grabber, slide the cable end into a 3/8- to 3/4-inch-diameter hole, making sure the cable feeds into the wall. Pull the piece of fish tape toward you while holding the handle still, then twist the tape half a turn. The cables will now fill most of the bay. Now stick your snake into the bay with an open hook on the end. Push the snake up and down in the bay until you hook the grabber. Pull the handle gently back to the end and gently guide the cable that is hooked on the snake out through the hole, pulling the snake out with it. (If your hole is bigger than 3/4 inch, be careful not to pull the grabber into the wall.) The snake grabber obviously works better in an uninsulated wall, but I have had some success with it in insulated walls, too.

Using a Tone Generator

Sometimes when I am having difficulty locating a snake, I use my tone generator (Figure 3), which can locate a conductor or other metal object.

Figure 3. A tone generator turns a fish tape into a transmitter. Using a speaker probe (or radio tuned between stations), you can locate the tape inside a finished wall.

To use the tone generator, I clip one of its leads to a snake I have fished up a wall. The tone generator causes the snake to emit an electronic tone that can be picked up by the tone amplifier. (An AM radio will also work adequately instead of a tone amplifier; for best results, tune the radio so that it’s not on a station.) Hold the amplifier or radio near the area of the wall where you think the snake is. The tone will get louder the closer the receiver gets to the snake.