On Sat, 25 Mar 2017 12:31:33 -0700 (PDT), noname
wrote:

Home built in 2005. These are interconnected Fireex smoke detectors (I believe because they have a yellow wire connected to the red wire). All the breakers are marked, but I don't see one for the smoke alarms.

Now I was away on business and my wife had an alarm chirping and couldn't get it to stop so she literally in wired it while it was hot! Could have killed herself.

Problem is I want to rewire it and I don't know how to cut the power to it since there is no breaker.

Thoughts?
There HAS to be a breaker. It will likely be shared with another
circuit - in USA the code required the smoke detectors to be on AFCI
breakers, I believe.they are GENERALLY connected to a bedroom circuit
- which also requires AFCI protection.. This is NOT a code requirement
but is acceptable best practice..