Scary moment
Poked my head out the back, noticed the air was deliciously cool. Decided to give the air conditioning a head start, since today will reach 92. Opened internal doors and turned on a fan in the bedroom to suck air through the house and pre-cool the bedroom.
After a few minutes, caught an unmistakable electrical-burning smell. Seemed at first to be all over the house. Poked outside again; not coming from outside.
ACK! Is the attic wiring burning?
Turned off the fan as a first step. Immediately the smell was less dominant, confined mainly to the bedroom. Leaned down and sniffed the fan motor directly.
GAARRGGGHH! There it is.
Took fan outside, ran hose on it until cold, then threw it in the trash. By the time I got back inside, the smell was gone.
Sort of sad to lose an old American-made possession: the Tesco fan has been serving every summer since 1974. But I guess that's a good long life for a gadget.
Later: to pin down the constants and variables, plugged a heavier fan in the same outlet and ran it for a while. No smell, so it was definitely the old fan, not the wiring.