I do absolutely agree with replacing the serpentine belt first. If you have never replaced it, you really should anyway. Five years is a maximum replacement recommendation.
Check your torque on the balancer and all of the other pulleys while you are in there, or make sure that the technician does.
The 'wobble' and 'squeal' often tends to come from the sound of dry rubber sticking to a pulley and causing lift or push on one side of a bearing. The wobble or squeal could also be a bearing in one of the driven accessories. If you can try to isolate the sound to one of them first, that might help you to solve another problem before it happens.
The old-fashioned way to figure this out is to take a long candle and lightly touch it evenly to all sides of the belt, and see if the noise stops (lubrication fixes almost everything at least temporarily). If it does, it is the belt (and even if the wax fixes it, replace it anyway). If it doesn't, it is a bearing somewhere (probably alternator or water pump, but those are just guesses).
Paul's suggestion is also excellent! In fact, you should do this first. Use a bright light on the passenger side at the front of the engine, and all of the pulleys should be straight while the engine is idling. If one is moving - replace that bearing. And then, replace that serpentine belt anyway.
