Display Auto adjust brightness acting weird and flickering

Last couple of months I get a fair amount of flickering on my screen. As far as I can tell, there

is no specific area that it is flickering in. After checking my settings for Auto brightness,, I find that

the box that is there for ticking off "Automatically adjust brightness" is unticked, and the brightness is

moved to around the 3/4 brightness area. I am in my basement which is fairly dark, so basically I am

trying to find out about the flickering that goes on, and have a feeling that when the brightness is diminished, it

causes/caused the flickering. So, I raised the brightness to extreme(right to the end of the scale) and continue

to have the box "Automatically adjust brightness" UNCHECKED. Sooner or later,, something must trip off the

Autobrightness,, because I eventually notice the flickering going on,, then I go to my settings to check the brightness,

and find that the slider is back to 3/4 and still the Autobrightness box is Unchecked. This happens all by itself.

Basically , #1,, whether it is on Auto or Not,, I shouldn't get any flickering, and #2,, my display shouldn't on its own

adjusting automatically the brightness by itself, unless I check the box correct? How can I get my screen brightness

to stick ?