Beginning Disclaimer - I am not a Serious DIYer. (I'm more of a Seriously Try to Avoid Paying Someone Else to Do Iter).
So anyways, I've been having trouble with lights flickering or not working in a room. I checked the voltage, and found that 3 out of the 4 outlets had quite low voltage (around 40 instead of the rest of the house outlets at 120).
After some investigation, I took out several outlets and found that the first problematic one appeared to have a wire that was corroded or burned. Didn't look really bad, but didn't look right.
I detached the outlet, cleaned up the wire with some steel wool, and installed a new outlet in there. Surprisingly that worked. This outlet and the 2 others in the room now have normal voltage and work fine.
So my question is - what would cause the wire to become corroded or burned like this? Is there anything I need to look out for?