Hello @cajoe,
Thank you for posting here in the Community about your QuickBooks files. I want to help you figure out what the files are for in QuickBooks Desktop for Mac.
QuickBooks for Mac has different file extensions compared to the Windows version. To isolate the issue, I recommend you identify if the file you're seeing on your end is a company file, backup copy, or another type of file.
It may be possible that the files in question are backup copies. For more details about the extensions and file types, check out this link: File types and extensions used by QuickBooks Desktop.
If you see unusual QuickBooks files you want to check further, let us know. You can include some screenshots to investigate the data further on your end.
Also, I've attached an article you can visit to know more about scheduled automatic backups for company files in QuickBooks: Back up your QuickBooks Desktop for Mac company file.
We'll continue assisting you with any concerns regarding the QuickBooks files. Let me know by leaving your response below. Have a great day.