Thanks for the reply.  Things are OK now that it's 20 degrees F!!!  I had pulled fuses earlier & swapped relays. I don't think the problem is there.  The car has 120,000 miles, so, then, most likely,  (wear & tear), and (temperature & humidity) - I'm cracking the windows a bit at night and I should put a heater inside the car to dry it out (hard to do in snow conditions).  Since, it's an intermittent problem and I don't do much night driving (more daylight now).  I will nurse and address better in spring/summer.  I was considering, if things failed entirely, I'd have to take it to the shop, and a switch and a key replacement - more expense.  I think the key must be  'mechincal' and pushes a pin to make a contact, but like you said, hard to say, which is the culprit, unless all taken apart.  Cheers.