I've had my 7800N for quite a while now and more than happy with it (first used on EE ADSL/ADSL2) but now on Plusnet (BT) Fibre (FTTC).
I've never had a problem with it hence why I've not posted before (but have found some useful info on the forum in the past) but recently I have been using my Wifi more often (I tend to switch it on when I know I'm going to use it for a while).
However, I noticed the other day on my Windows 7 list of available Wifi networks that there was a SSID name that I recognised from a long time ago that indeed I had created for some reason I can't remember in the days I had EE. I always set my own recognisable SSID and I don't broadcast it.
I can connect to my proper SSID on my Billion 7800N perfectly OK, but for the life of me I don't know what or where this other SSID is but I know it's coming from my network because a) I created that name many moons ago and b) it disappears when I switch the 7800N off and re-appears when I switch it back on

I have even installed the free version of Acrylic Wifi and found that the MAC address of this "ghost" ends with the same characters as that "ghost" SSID, that it's capable of the same speed as my proper SSID (and of all the Wifi networks I can see, mine are the only two that show that speed) but that it's definitely showing up as being manufactured by TP-LINK (and the 7800N correctly shows as Billion). Interestingly though is that the signal strength from my 7800N is 5 bars as I would expect yet the "ghost" TP-LINK device is only 2 bars. Also, the Wifi channel numbers that it finds and the type of encryption keys I use are exactly the same for both my 7800N and this "ghost" so I'm sure it's coming from my network but how?
I have done a "factory reset" of the 7800N and the flash version is 1.06h so I'm really at a loss to understand what this TP-LINK related SSID is. The only TP-LINK kit I have on the network is a Homeplug system but these are purely LAN related with (as far as I'm aware !!) no Wifi capability and I can see their MAC addresses from the Powerline Utility and they are different from this "ghost" SSID. I have even tried unplugging the Homeplug units but that TP-LINK SSID still shows up. The Homeplug units are also assigned a name that is not the same as this "ghost".
Does anyone have any clues as to what may be happening. I'm sure the "ghost" can't be logged on to (I've tried using my main SSID password) but it's just bugging me as to what it is and why it's showing up.
Thanks
Colin