Jobs at small Louisville companies nobody posts about - 4 months and counting

A friend who works at a local manufacturer says there are openings not advertised online. It has been weighing on me all week. They like a brief email with a résumé. Should I visit in person?

Keep everything in writing and save the confirmation numbers. It saved me later.

A short email with two sentences about what you can do and your résumé attached worked for me. I followed up after a week.