Toyota Repair: stall, corolla wagon, coil wire

Question
I have a 1990 corolla wagon. My car has now twice stalled out, making the car unable to drive. I brought the car to the mechanic and he is unsure what it is - because it has ran perfect for him all day. After letting the car sit for a while I am able to drive it again. The only thing in common is that it has rained prior to the stalling.  

Answer
The problem is electrical, there may be a shorting to ground at the ignition coil or coil wire, the problem can be duplicated by spraying the ignition wires, coil, distributor with a spray bottle filled with water, the mechanic should be able to isolate the problem by doing this.