Ring 2 doorbell keeps ringing when nobody there!

Hi. My ring 2 doorbell has suddenly started ringing as if someone is at the door and pressed the bell, but nobody is there. It started last week and is gradually getting worse. Overnight it has gone off at least 10 times! I’ve got the latest app, have rebooted my device, have rebooted my phone. Nothing seems to fix it. Has anyone else had this issue and found a resolution please?