turn signals flashing, malfunctioning

What is your question?

My turn signals just went nuts....rapid flashing instead of the signal. The turn lights on the mirrors are fading too. It seems that something snapped. I do not see any damage to any of the bulb covers and I could not find any burn't fuses. From what I have read, it seems it may be the turn switch assembly (the whole turn stick) or square, black fuse box under the steering column. Anyone know for sure? My 2006 tahoe has 52k.