Why does my alarm keep going off?

My brother just got a 1997 GST a few days ago and the alarm goes off once in a while as if its short circuiting. I don't know where to look for that at because im not especially into the eclipses. I have a Civic. anywayz i goes off whenever it wants basically except when we are driving. also how do you change the fog light bulb? thanks

Is this the stock alarm or aftermarket?

As for the fog light, they are a PITA to replace. The one big bolt that holds the fog light housing in is usually rusted pretty bad and hard to get off. Basicly you just let it soak in WD-40 or whatever your choice lubricant for a few days if you have trouble. To replace it, you just take off the front cover thats held on my one screw, then you will see several screws holds the housing in place. Take those out, swear at them a bit for good measure. Then once you get the housing out, there are a few screws to get it apart. Then it's just plug and go with the new bulb and put all the screws back.

It is a stock alarm

That problem is very hard to diagnose becuase the factory alarms are programed into the ECU. It recieves its signal from various objects on the vehicle. Mainly the door switchs. If you look in your door jams you will see a little switch that tells the ecu when the door is open or closed (if you push the switch in and out and your open door lamp goes on and off you have the right switch). Make sure those switches are working properly, if they are malfunctioning this could be causeing the factory alarm to go off. Other than that you may have an ECU problem.