Gave an old panel its last handshake today

Forty-year-old switchgear, copper busbars worn smooth as river stones, and when I put the meter on it the hum changed key, like it knew someone was listening. I didn't replace it—just tightened a lug, cleaned the corrosion off a knife switch that outlived three owners—and stood there a minute too long. Every time I close a cabinet on old copper I swear it's saying something, and tonight I almost wished I understood the language.