Lincoln/Mercury Repair: 93 cougar xr7 CEL and light & lighter 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,

There is probably a bad fuse causing some of this. I would replace the light switch. For you to do it yourself will depend on your experience with working with auto electronics. The check engine light is not coming on because of the light switch nor it needs an oil change. The check engine light is connected to dozens of sensors and we need to know what codes are present. I suggest you have your car scanned and resubmit to me the code numbers so I can make the proper recommendation.