This way you have the best of both worlds. Because were only making an in wall extension cord there isnt any reason to turn off the power.
Previous Owners Had A Wall Mounted Tv With Power Cord Running
Can you run tv power cord behind wall. If you want to safely run cables and you need to get power to your television or other devices but need an outlet. If so you can add a receptacle rather easily behind the tv. Does the power cord run straight from the outlet to the tv or does your tv use an external transformer. Instead a wall kit will put a power outlet directly behind your tv and run cable safe wire down to a plug where youll attach an extension cable. Feed the wires through the retro fit single gang box and then screw in the screws to secure them. Hiding the cord while remaining within code and not having any future problems.
If it does then its legal to run low voltage wire the wire coming out of the transformer through the wall. An extension cable to run to an existing outlet. Its legal where i live anyway. It can be done but if a fire results from this then the insurance company may find a reason to not cover the damages. If you ran the tv cord through the wall there must be an outlet receptacle nearby. The only power cable you should run behind your wall are ones that come in a code friendly kit.
Youre supposed to have a new electric socket installed directly behind the tv where you can plug in. You should not run power cables through a wall as a substitute for permanent wiring ie wired outlets. In other words running power cords through the walls is not a substitute for permanent wiring.