94 Grand AM

I have a 94 Grand AM SE 4 cylinder 2.3L I bought it off my boyfriends mom about a month ago and for some reason it stalls when it rains, it didn't do it to her when she drove it, but she parked it 3 months before i bought it, but the tiniest bit of rain causes my car to stall when i start it up, does anyone know what could do it?

Check the bunch of wire going into the coil cover, sounds like a mouse might have nibbled on a few wires.