1998 Nissan Altima Car randomly honks, locks & flashes.

About a month ago. I was in my house and all of a sudden I would hear my car honk at first it was kind of random and could be seperated by a few minutes. I eventually was able to be outside while it was happening and saw that it was flashing and that the doors were locking. This is all things that would happen if I locked or unlocked my car with my keyless entry when it was still working. Eventually this same night it was honking and flashing every second and as I listened to the door locking it was doing it so fast that it sounded like it was possesed or something. I actually had a hard time getting into my car to pop the hood because it would lock itself as soon as I would turn the key. So I eventually unhooked the battery. Once I hooked the battery back up I heard it honk for no reason once while I was doing yard work. Then again today I had a repeat of the first incident where it was so bad I just had to unhook the battery. I've only caught it having issues at home but my fear is that this might happen when I'm not around to unplug the battery. Like yesterday when I wasted my time at the Seahawks game. :-) Any thoughts or ideas?

-Jason