Why will transmission shifter be stuck in park? What are possible causes? on 2009 Kia Optima

Our 2009 Optima will not shift out of park. Checked possible fuse problem, the ones I checked were fine. Really wasn't sure which one to check. Upon further investigation, with car running, I attempted to shift from park. In my attempts I noticed a clicking sound inside car from underneath near the firewall, it sounded almost like a relay kicking in and out. It wasn't a linkage type sound (like older cars with bent linkage hanging or rubbing). Any suggestions short of a KIA dealer mechanic.. If I know what to look for, I can fix it. This first time this has happened to me ever.

Asked by for the 2009 Kia Optima
shift lock cyl not functioning.ck brake light switch to start with,this is what activates the release
the car is at KIA under extended warranty, entire shifter is bad. "they" said anyway. it's covered all but $100, thanks for your help though..