Puzzling Electrical Issue for Saturn 2008 Vue

Well, it happened again. Took it back in to have the ground-to-chassis looked at, but they said it was fine. Battery connections are good. I will check connections in the box on top of the battery and fuses, but this exercise sounds like one of the first things a mechanic would try. The biggest obstacle is that it’s intermittent, and apparently can not be duplicated on demand. So that means the next time it happens—likely at night when my wife is out running errands or shopping in a month or two—I’ll need to go out to the car. But history tells me the car will “come back to life” by the time I get there. Wish I knew how to use a voltage meter.