An electrical short to ground.
smoke, bubblegum, and your mom
It would depend on what is burning.
A rubber burning smell and smoke near your two front tires could be the result of sticking calipers. The brake line could also be the cause of the burning smell.
If you can smell burnt plastic then you could potentially be in danger. Smoke from burning plastic can be harmful to breathe.
because the fan belt is burning
The smell was dead bodies being burned to ashes
An air conditioner should not smell like smoke when turned on (or when turned off). I would have to suspect that the electrical insulation is burning.
Volcano smell like rotten eggs or sulpher..
If awake you can see the smoke and smell the burning odor. If asleep you rely on your nose and if smoke is inhaled your cough warns you of fire.
pcv system is clogged up.
Possibly a problem with one of your belts?
your car is burning oil.