it runs
OMG the pig!
You are wry
I gotta ask what work was done recently I cant remember right now check back
Now that I tihnk of it, it does come on consistently w turning on AC and stops when a/c turned off(not using it now) but it also does it randomly other times and stops randomly

Belt noise from worrn belt.
Belt noise from bad bearings in water pump, a/c, power steering, power brakes, alternator, smog pump ,etc.
Brakes are down to warning sensor.
Wheel bearings worn/dry.
Pig stuck under the seat.

More detail'sd help. What's squealing? When? Recent work?