In a nutshell it allows you to run 120v through the wall without needing to run the wires along a stud. They can cause electrical fires if there is a cut or another issue with the cable or device.

How Do I Run Cable Through My Ceiling Home Improvement
Run cable behind wall. Strip the wires and attach them to the wall jack or run them to the device. We bought the powerbridge one cable management system. Feed the wire through the back of the outlet box insert the box in the wall and mount it in place. Run electrical cable through walls and across ceilings without tearing them apart. Attach the fish tape to the cable after the blade of the fish tape has been retrieved through the box opening in the wall uncoil enough nm cable to complete the cable run you are planning. Make sure to allow about 2 feet of excess cable at each end.
In other words it makes it easy and safe to run your power cable. The installation was very straight forward and simple to follow. When you hook cable to the eyelet of a glow rod strip the plastic sheathing back about 6 in then cut off the hot and neutral wires. Place your tv back onto the wall and plug the tv power cord into the top receptacle box. Then wrap the remaining ground wire through the rods eyelet and wrap it back around the wires sheathing several times. Stretch out the cable and untwist any kinks in it.
How to move an electrical outlet behind the tv mounting a tv to the wall part 2 duration. This is the perfect solution to have the aesthetics you want in your home and being sure that your family is safe. Really the only cable you absolutely should not run through a wall is a standard power cable that plugs into an outlet. Learn how with this video. It is perfectly safe to run most cables through a wall. It was around 60 and well worth the price tag.
How to run cable through the wall demonstration. These cables will heat up more than most other cables. Alan clegg 1022182 views. Drill destination hole in floor. Cut two holes place the unit in the wall and run the cable. Finally wrap the whole area with electrical tape.
Connect your other cables as needed. Plug the included power supply cord into the inlet box and the nearby wall receptacle. Run wire through hole. At the time i didnt know that running your tvs power cable inside the wall is not up to fire code.