Things You'll Need
Wire finder/mini locator
Coaxial cables are thick cables that carry a large amount of information, like cable television and high-bandwidth Internet signals, from a cable company or Internet service provider to the user. Most homes and apartment buildings have these cables and connections already installed in the walls, much like electrical outlets are already installed. But sometimes these cables get lost behind the drywall, especially if the location has been under construction. Specific tools are needed to find these cables.
Find Hidden Coaxial Cables
You will be using a tool that will locate wires inside the walls with a transmitter and receiver, and other objects in the way of these signals can give mixed results. So clear the room where you're trying to find the hidden cable, or at least clear the wall that you believe the coaxial cable is hiding behind.
Set up a wire finder/mini locator device. There are a number of these tools available from different brands, and they operate in different ways. For example, the Greenlee 508S traces wires behind walls or dropped ceilings. It has a built-in transmitter and receiver that allows it to trace wires at depths of up to 3 feet and lengths of up to 1000 feet. The locating tool can be plugged into the wall or can run off two 9-volt batteries, allowing you to transport it just about anywhere to locate coaxial cables, even places without source power. These tools range in price, but most cost at least a few hundred dollars.
Locate the coaxial cable using the transmitter. The mechanism for doing this varies depending on the transmitter, but is often as simple as turning on the device and pressing a locate button. The tool will indicate how far away the coaxial cable is and will adjust its readings as the locator is moved closer to or farther away from the cable. This way you can pinpoint exactly where the coaxial cable is in the wall.
Once you have located where the cable is, carefully cut a hole in the wall and retrieve the hidden coaxial cable. Make sure the hole is smaller then an outlet cover, so the coaxial cable can simply be run through it and the outlet cover can be placed on top of the hole you cut.
When cutting the hole in the wall, be careful you don't cut into the coaxial cable itself or other electrical lines behind the wall.