Tv above a gas fire place and need to hide the wires.

Please don't do this! You would require a much larger space between the fire and TV, as heat rises it will dangerously heat up the bottom side of the TV. In my opinion highly dangerous, you would need at least 1 meter distance to ensure heat transfer to TV is minimal

Honestly? I wouldn't.. the T.V. Will get hot and you will lose your T.V. pretty quickly if nothing else dangerous! I've seen this happen a few times, it seems the place to put it when the whole room is based around the fireplace as a focal point, but it isn't the best home for a T.V. it has vents in it for a reason and that's because they get hot through normal running and need to cool down. Allowing more heat to rise into the device isn't the best idea! 🙂👍🤷‍♂️

The only way to hide wires is chop out a channel in the plaster to bury them. The same as you would to install cables for sockets. You need to keep any AV cables separate to the electric cable to avoid interference. Or install them inside trunking surface mounted. Each situation is different/particular to the house but if you want to hide the cables you have to hide the cables and replaster the wall channel. There is no easy option.

Totally agree what the comments about heat. It’s a viewpoint that has lost me thousands of pounds worth of work but, it’s something that shouldn’t be done.