Nissan Repair: 97 Altima electrical problem, phillips screwdriver, low beams

Question
One more question...I have a Chilton's repair manual for my car, but nowhere in it does it say anything about a master switch. I looked at everything I could find on the steering column and made a phone call to an auto parts store. They priced the switch at about $150.00. Does that sound right? Am I looking for the right thing? I guess what I'm getting at is...what the heck is the 'master switch'?
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-----Question-----
When the headlights are off and the brake pedal is pressed, almost all lights come on (brake lights, parking lights, dashboard and console lights, side marker lights) and the radio quiets a little bit. There is a loud click coming from my shifter. Idiot lights on dashboard do NOT light up. When headlights are ON, brake lights are constantly on (both right and left and the one in the rear window) and glow only slightly brighter when brake pedal is pressed. Also, interior lights flicker slightly as brake is pressed. Cruise control function no longer works, but I'm not sure if this stopped working the same time my lights began acting strange. Also, the mechanics where I bought my car "deactivated" my air bags because the air bag light began flashing constantly. The air bag light (if I remember correctly) no longer came on when first starting the car, but does so now. The air bag was sensors were deactivated a couple of years before my current problem with the lights. All grounds and connections I could get to appeared to be in good order. Any thoughts?
-----Answer-----
Sean,

Sounds like the master switch on the column has gone bad.  The lights all feed through the headlight blinker switch.  it is an easy replacement and only requires a phillips screwdriver.

Answer
Sean,

Yes, the headlight switch is the master switch I am talking about.  The switch does it all from turn signals to headlights, highbeams and low beams.  So, I call it the master switch.  rockauto.com is a cheaper alternative if you can wait for the part to come in the mail.  You could save something like fifty bucks.