is there any reason a mechanical egt gauge would be pointing to 6, when im at 5500+ rpms and accelerating hard?

usually it would be at like 11-12. last night, it seems to be running ok, just stays low all the time. sometimes it actually seemed to be higher when i was going slower, unless i was just imaging things.

when my car is at idle and even sometimes when im cruising, the egt needle bounces around a lot. i mean REALLY bounces, it would bounce from 6 to 10 repetedly at like a million mph. could that have to do with vibrations in the exhaust?

also, what does an egt gauge actually consist of? the guy who had the car before me put it in, so i never saw it. I know there is the power wires for the light, but is there like a vaccuum wire or anything, or like one big sensor wire?