I'm not actively using any app that uses the camera.
First thing to do would be to simply quit each app in turn, and see if the camera light goes off, until all apps are quit and only the Finder is running.
If the light is still on while only the Finder is running, then that's a problem. Look at the list of processes that are allowed to access the camera in System Settings > Security & Privacy. If there's nothing out of the ordinary there, and the light is still on, then I'd suggest ensuring that you have a current backup, erasing all user content (System Settings > General > Transfer or Reset), and then restoring your data, but not apps.
