?( that sensor below idle adjusment screw)?

Okay,
I posted a few days ago, that my Geo metro 3-cyl hatcback
continues to idle to high after warm-up. The thermostat in the car reads between a 1/3 and 1/2, so I'm ok there.
Well this morning, I removed(disconnected) that green switch(plug) just below the idle adjustment screw, and the car idled normally at that point. If I plug it back in "up goes the idle again".
1st, what is this switch contolling?
2nd, if I disable it(keep it disconnected), will I be doing any damage?
3rd is it operating properly by regulating the idle of the car.
I'm wondering if that switch is telling the car to run richer then it needs to after the car warms up sort of like a choke would operate. I am only getting appox 29 miles to the gallon. Yesterday I replaced a bad catylitac convertor and a stretch of leaky pipe, so I'm hoping mileage improves, but now I'm wondering if this switch might be the culprit or at least involved.
Does anyone know the particulars of that plug, and what it means to disconnect it?
(Again, it's right below the idle adjustment screw on the right side of the throttle body).
Ant thoughts, would be greatly appreciated.

Dave (lakini)

check on your throttle body just below where the idle screw cap is, you'll see a allen socket screw with a 10mm lock nut, back off that nut, then back out the socket screw and see if your idle drops, I had a high idle problem with my 92 1.0L and that cured that problem. It's the throttle stop screw.

Also, that could be your throttle position sensor, not sure without looking.

I'm afraid to make a throttle adjustment, because when I remove the switch(plug), the idle seems perfect. So it seems everything is set right, just that a senor is possibly reading wrong.