Are you talking you seeing an SSID called “hidden connection”?
You can go on your wifi router to see it its on it
You can also have other Wireless devices advertising and SSID things like a wireless printers
You can download a wireless tool app on your phone and go sniffing around
to find the device by signing strength...
No when I open my wifi there on the list is an option called hidden network. and it is secured. And it needs a password. And my password doesn’t work on it.
now its gone. It seems to come and go.
You know, someone in the building wears a cpap. Cpaps now communicate with their doctors to count the hours in use each night. I wonder if that it what I am seeing. I will check in the AM with the cpap wearer.