virtualpostmail.com can get you an actual address to receive mail at. Doesn’t raise any flags like a PO Box. Can receive and forward packages too. Not totally anonymous, you need to file the USPS CRMA mail receipt form with some identity proof but after that, you get a reliable non-home address for packages, signing up to websites, etc. I’ve used them several years and not having to put my actual residential address on much has been great.