|Most routers use very similar ip addresses to access their management pages - locally. Locally means when you connect to it via cat-5/ethernet cable. If you have enabled wifi and use the login address then you can indeed get to the same management pages; but first you have to provide the correct access-key (frequently incorrectly called the password) to actually logon to the wifi itself - before you can gain access to the management areas.|
A routers "home" address is usually a variation of 192.168.x.y - where the usual variants are either 192.168.0.1 or 126.96.36.199 There may be others too.
If an unauthorised third-party tries to logon to your router via wifi - they must know the SSID and the wifi access-key first. Then presuming they know that they can, using the correct variant of the router's ip address, login to the management areas.
Way to prevent any unauthorised access via wifi? Change the default access-key; and make a note of it in more than one place. Stick a note of it on the base of the router; email a copy to yourself and save it in saved folder in your on-line email account (free cloud storage). Even more control - enable mac filtering; which allows you restrict access (via wifi) - and allow/permit only those devices in the list..).
As per Derek - afternoon Derek - what make/model router do you have?
What is the name of the router you are seeing and which you think is the same as yours? You can occasionally see two wifi access points in your list of wifi access-poiints in your immediate area - which will appear to be the same; but on closer inspection you they will have slightly different numbers or letters too.
For example in my area there are several Virgin wifi access points (routers) and also SKY. The Virgin routers start with VM, the SKY with SKY. Each then has numbers after the VM and SKY accordingly. Also if there are wifi extenders around they will have almost identical SSID to their parent router. Thus for example a wifi extender "attached" to/working with a Virgin main router VM12345 - that extender will show as VM12345-2 or VM12345-5 (depending on its wifi facility).
Is this what you're seeing - not necessarily of course either Virgin or SKY; depends on where you live and what isp facilities are in your area?
Back to access-kep/pass-phrase. The default for each router is (allegedly) unique; but just like car keys - there may be a limit to possible variants? However I haven't ever come across a router with the same default/factory access-key/pass-phrase as another (whatever make/brand).
So with the above info in mind, and echoing Derek, what exactly are you seeing? Also do you know how to login to your router's management/setup pages/areas? And again make and model of your router. And also perhaps list the SSID of routers (wifi obviously) which you see in your area - including yours?
Do NOT post your (or any) access-key/pass-phrase details here; or in any open forum. That's asking for trouble...