Possessed mouse

I have 2 Win7 pro pc’s that the cursors moves around the desktop, clicks on icons and opens files, even does a right click on the desktop to open the properties tab. If the database is open it clicks the icons to open different fields, but never alters any data. I thought it may have been a faulty mouse so I unplugged it, still does it. Disconnected it from the network in case it was a remote access issue, no. Scanned it with AVG & Malwarebytes, nothing.
If i move the mouse around myself it work perfectly, but about 60 seconds after you stop using the mouse, off it goes on its own.
Any ideas greatly accepted.
Thanks Puzzled.