Guys, you are making far to much of an issue of the proximity of the mains socket.
The issue here is the standard of the wiring that is being used for (any) extensions. It looks like it's probably alarm cable, it is certainly not CW1308 standard telephone cable.
@novak100
Don't even think about reconnecting any of that wiring for possible use by your modem/router. If you wanted to make an extension socket live for phone use using that wiring, you would need to use a filtered faceplate otherwise connecting it direct will result in lots of interference being picked up and this will have a major impact on broadband performance.
Also you should sort out that right hand screw hole on your master socket. The picture isn't clear whether it's just filled with silicone because the screw is missing or whether one was broken off, but without a proper screw there your connection of front plate to the back plate may be unreliable and give drops on your broadband. You are better leaving the filter in the Test socket until that is resolved.
Also do not use any "regular" extension leads between the socket and the filter, or the filter and the modem/router.
HTH.
