How to go about selling an unused CPU locally

So I built my PC, and it runs great. But my cpu got lost in the mail so I got a refund and bought another one. A week later, the "lost" one came in the mail. Now I have an extra CPU lying around. How would I go about selling it locally?? I don't trust the mailing system so I'd like to sell it to someone in the area. I was considering making a post on my university's subreddit but I'm unsure if that's the right call.
It is an AMD Ryzen 5 7600 cpu if that helps.