do not even bother to clean it
Clean and adjust the shift possition switch on the left side of the gear shift assembly. The "P" light on the dash should be on when the shifter is in park.
,, i had 2 of them go bad on me, removed them, cleaned them but it did not help, as soon as i replaced it,it worked normally .....
But like Chio said , a good indication of that position switch going bad is also that the P LITE on the dash will not lite up , then if you play with the shifter lever and push it a bit more and hard toward the dash the P lite will come on .
Also both switched were acting up as weather was getting colder ..