Hi
bohica and welcome to the forum.
I changed mine to wired to eliminate the noise (visual as well as audible) with the wireless cameras. Too much interference from things like cordless phones (mine & most likely my neighbours), household obstacles, distance, direction, etc.
Result: clean video and only the sounds picked up by the cameras.
I used 4-wire phone cable since I had a lot of it already available. 6-wire with running separate grounds would be ideal.
I did use RJ11 connectors, but I made a junction box that these plugged into. This box joins the cameras signals together and distributes it with RCA cables to a
Cable Modulator which in turn distributes the signals to all house TVs & computers via the existing cable system on an unused channel.