Needs to be refrigerated: Yes
You may have heard that hard cheeses can stay outside the fridge safely. Not so. Refrigerate Swiss, cheddar, or any blocks of hard cheese, where they’ll keep for about a month after they’re opened. If you spot some mold, cut it out along with a one-inch chunk all around it. Then rewrap the cheese in a fresh plastic. Don’t try that with sliced cheese though. If there’s mold on one slice, toss the rest.