doors wont lock when lights are on?

ok ive had probs since i bought the jeep witht he drivers door locks switch in the beginning i thought it was the switch.
but now i have figured a few things out.
drivers door switch wont work when key is in ignition
drivers door switch wont work when the lights are on.
Pass side works all the time..
are there any other times it wont work?
because with the keys out and the lights of sometimes it works sometimes it doesnt im thinking i still have a switch problem somewhere.
any ideas..
whats it take to pull the switch out?

the light switch? if so its a pain in the arse to get to ... getting out not bad trying to get it in ... misserable ....

under the dash u can feel the switch theres a lil button u push and the pull knob comes out there theres like a screw thing the knob goes through that comes out with a flat head and then the hole switch thing drops ...

no the door lock switch.