''P'' on shift selector stays lit

The 'P' (park) stays lit with the trans in park, engine off, and doors locked.
It never goes off. If I don't use the truck for a while it will probably killl the battery (?)
Any ideas?
Angelo
2009 EX EB

This is the answer

''When I have my Explorer parked and off, the 'P' is colored red and is differently colored than the rest of the gears. Is this what you are seeing and you believe it to be illuminated? ''