I go into the living room, and sure enough, it's ringing, but it's really weak. I pick it up, and it's a dial tone.
So I call the marmot line. It's busy. Ruh-roh.
Something is indeed screwed up with the phone lines.
I go into the basement.
Now you may think that in my McGyverish tendencies, I've set up the phone wiring in a big terminal block in case I need to do some troubleshooting on the phone lines. And you'd be right. Usually when weird phone shit happens, it's outside the house, so I disconnect it from the incoming block and use my handy test phone to check the lines.
This time, the incoming lines are good.
I do some fiddling. I start disconnecting branches of the phone lines and do some testing, but when I call on the main house line at the incoming block (that is absolutely disconnected from the rest of the house), the house phone rings.
Something somewhere has crossed the lines.
The first suspicious culprit is the line that actually runs OUTSIDE the house to go to the upper floor.
I keep disconnecting lines until I find the culprit-- which is a branch line that runs to the front of the house.
So I get there and start disconnecting lines. Third try is the charm-- one of the now-unused jacks in the living room, behind the TV. Weird, but okay. I disconnected the wires and went upstairs.
The jack was latying on the floor, upside down behind the TV.
It was full of cat pee.
And evidently, cat pee has some rather interesting properties when it comes in contact with copper wires, brass screws, and electricity. It becomes conductive at just the right amount to bridge the phone circuits without shorting out either one of them.
So now I have to wash up all of the cables, try and de-pee the place, which is right behind the litterbox.