Open electrical circuits?
OK, First a "chirper" measures the magnetic force around an ac current carrying conductor, but it does not identify the strength or the amount of power of that conductor. So you may be picking up trace voltages. Since you mention knob and tube also romex, I am assuming that it is an extremely old system and it has been modified probably more than once.  Knob and tube and some older romex systems do not have grounding systems. It also means you may have a switched neutral which was legal many years ago (like 75 years).

I suspect that you are getting a certain amount of feedback power through the neutral from circuit 8 and circuit 18.
When you add the comment that ceiling lights are constantly burning out it may be confirming that you are experiencing "floating" power and the variations of the power is not good for the life of any lights or equipment. For example, if your lights are dimming in the kitchen when you turn on a hair dryer in another room, that would also indicate a "floating neutral". The only other reason you would be burning out lights is that you're buying cheap lights.
If you are not experienced in electrical power I would suggest professional help. If you want to try and labor through it USE EXTREME CAUTION. 

The first thing they teach in electrical apprenticeship training is to always treat everything as if it were hot unless you are absolutely sure it is dead. In your case turn off the entire panel.