I've replaced the camshaft synchronizer (Mazda calls it a C-shaft transducer) previously when I had a squeak, or I had a trouble code, I can't remember which.
Recently I had a chirping noise, it could be described as a squeak at times. It would come and go but seemed to be getting worse, so I picked up another synchronizer at Napa, thinking it was time for another one. It had been several years, about 60-80k miles, probably. I had the new part ready but when I took off the camshaft position sensor I found the magnet had come off and was stuck to the vane (the semicircular part of the synchronizer) and all I had to do was replace the sensor. The first picture is the part in place on the rear of the engine. The second pic is the "made in mexico" bad part. The third pic is the magnet that is supposed to be in the "made in mexico" part, down in the synchronizer. Needless to say, I removed the magnet from in there. I replaced the CPS and the noise was gone. I got lucky this time. I thought I'd pass along in case someone else had a similar sound. you might want to peek under there before you panic.