Lincoln/Mercury Repair: cougar xr7 CEL and headlight switch, cougar xr7, serpintine belt

Question
My 93 cougar seems to be an endless batch of problems these days and i have worn my self extra low in $$$ getting everything fixed.
For a while my light switch had been acting very odd. having to just pull in it lightly enough to get both internal and external lights to go on while driving at night. Suddenly out of no where while im driving the headlights and internal lights flicker on and off all kinds of crazy. so i pull out the nob to just get the headlights on, and now those go out while im driving and start flashing.
At the same time this problem started my CEL has come on and gone off every now and then. So being that i was due for an oil change i had that done but the CEL still comes on. And my lights are still crazy.
I had given my car a tune up new tires and that part that lets the break fluid get to the breaks, and a new set of breaks, and a serpintine belt, and an oil change and had the mechanic go over everything and fixed everything that was wrong which was pretty much that except the odometer ( i have no idea how many miles are on my car) & the bits of plastic that let my windows roll down, (so im pushin those down atm)oh and the cig lighter is busted as well,this was 4-5 months ago...
any way back on track. being that i did all that and nothing showed up then do you think my CEL is coming on because of the possesed light switch? And do you think i have a loose wire or i should just replace the switch all together?
And what would I need to do to replace the switch or fix the wire myself.

Thanks for your time and i hope you can help me out =)
~K


Answer
Hi Kim,

First, I would replace the light switch. Second, find a real mechanic because this guy should know that the check engine light is NOT telling you need an oil change, but that there is a problem with an electrical circuit in the car. The check engine light is tripped by dozens of sensors. To ignore it is asking for serious trouble. It is likely a bad fuse for the cigar lighter which also might be a fuse for something else that could be causing the check engine light. I had a bad light switch in a sable I gave my son for his 16th.