1999 Suburban help-under dash

[bretcopsey]

There is a defective switch or module under the dash that controls locking the doors upon turning the ignition on as well as turning on/off the courtesy lights. The other night, my interior light was turning on/off at will while driving. I had to remove the fuse to get it to stop. Now the "box" under the dash is clicking, sounding like morse code. It does this intermittantly. My questions are:
a) What is this switch/module called?
b) Besides the door locks and interior lights what else does it control?
c) Can I just unplug the harness connection to the switch without disabling the door locks and dome light alltogether? I don't like the design of how the doors lock as soon as you turn on the ignition. I wouldn't mind if it waited until the transmission was put into gear as with my wife's Venture.

[HILROD]

It sounds like the dome door switches or the switches are in the latches in some trucks. Also I've seen the hinges get loose letting the doors move back out of switch range

[MrQuick]

Check with the dealer, its probably that or a bad door lock cylinder switch.