Car Alarms: Factory-Installed Alarm, mercury villager, alarmtek

Question
My 1999 Mercury Villager minivan's alarm goes off by itself without anybody touching anything. Is there a part/module I can buy and replace the original one?
Thanks

Answer
I need to determine whether it's a factory alarm
issue or, if it's an aftermarket system you are
dealing with.

Is it: Headlights flashing, car horn honking
and a worded SECURITY" light in the dash flashing?
Or,
Is it: flashing parking lights,
an LED in the dash area, and a siren
"going off"?

Let me know more on this to better
advise you on a course of action.

Best Regards,

Robert Martin
CEO/ALARMTEK
DELUXESERVICE.com