Do I have a mold problem?
No, it's you. "Fairly clean" doesn't avoid foot greases. Actually, the real problem is carpet, it catches &amp; holds EVERYTHING...if floors could talk.

Including you &amp; mold &amp; allergens &amp; viruses &amp; enormous amounts of bacteria if it isn't literally shampooed semi-annually.

The likes of Wood floors, Tile, Finished concrete &amp; Vinyl flooring harbor almost nothing &amp; can easily be sanitized or even sterilized compared to rugs &amp; carpets.