Remove all files stored on Airport wifi station

Perhaps this support article may help resolve the

matter of clearing an internal storage from "Airport

Time Capsule" (w/ wi-fi base.)

..If you’re using an AirPort Time Capsule

you can use AirPort Utility to erase its disk..

.Note various macOS versions in these instructions.

{.From High Sierra 10.13.6 •thru• macOS Sequoia 15x.}

Erase an AirPort Time Capsule in AirPort Utility on Mac - Apple Support

//support.apple.com/guide/aputility/erase-an-airport-time-capsule-ap20913/6.3.9/mac/10.15

See also

Change your base station’s name and password

If you forget your base station or Wi-Fi password

Before you give away your base station or Time Capsule

(these ^ show various system-related ^ instructions)

•AirPort Utility User Guide for Mac - Apple Support•

//support.apple.com/guide/aputility/toc/6.3.9

Open Airport Utility (Applications > Utilities > AirPort Utility

Click on the Time Capsule

Click Edit in the smaller widow that appears

Click on the Disks tab at the top of the next window

Click on Erase Disk

Select the Zero Out Data option to securely erase the disk.

Click Erase

This process will likely take 6-8 hours. The Time Capsule front panel light will blink amber during this process. You will be notified when the process is complete.

Open AirPort Utility again

Click to select the Time Capsule

Click Edit in the smaller window as before

Click the Base Station menu item.....up at the very top of the screen where you see other menus like File, Help, etc

Click on Restore Default Settings

This will security erase all of the network settings on the Time Capsule

And.....you are done.