Hello, I'm sorry I'm no good with technology, hoping to try to solve this problem and find a UK based person. I'm located in the UK and my wifi/landline provider is BT.

Last year I had a home security CCTV system set up, using a simple HIK Vision computer with two external wired cameras. The security firm added two TP link cables, one plugged into the cctv computer & wall socket, another plugged into my BT router & wall socket and said the cctv would work better because the two TP link cables would run my wifi through electrical cabling (sorry for my basic jargon).  A while later, I noticed that when I logged into the online BT router information webpage, that it showed my neighbour's ipad and iphone as connected to my wifi.

- When I disconnect the TP link cable that is in the cctv computer but leave the second TP link cable connected to my BT router, it still shows her as connected to my wifi

- Then if I also disconnect the second TP link at my BT router, her ipad and iphone clearly become disconnected.

...in other words, both or either of the TP link cables, when plugged in, seem to enable her to connect to my wifi.

However, without one or both TP link cables, my wifi/cctv access is very much weaker (and my cctv phone app struggles to open the two camera views), so I guess that means the TP link cables improve my wifi.

I have spent months trying to ask the cctv security company but they just refuse to engage. I also spent months trying BT/Openreach, who again refuse to help.

Is there someone here who will understand what is happening and be able to provide me with a solution? (from general internet search, I got the idea that there might be a 'joint' electrical cable that the neighbour and I are using...but the only one that could be might be the external BT cable that runs into both our two terraced cottages (I think). But BT/Openreach have refused to help check if that's the case.

The label at the back on one TP link plug says:

model: TL-PA4010 (UK0 

Vers 3.0

AV600 Powerline Adapter

There is also a Powerline MAC number and a Powerline Key number

Hopeful thanks, Kostandia