Are you driving in water and want to know how many fathoms deep it is.


Or....are you looking for a phantom alarm?
You're going to try different things that are typically connected to alarms. The first would be the leveling jacks, make sure they're all completely up. Maybe disconnect power to the jacks and see if the alarm goes.
The next could be a parking brake alarm.
You may need to get a code reader, plug it in and see if there is an engine code present. Auto parts stores like Auto Zone will plug in a reader for free.