my 04 Sportsman 700 did a weird thing yesterday.  I turned off the key after a short ride and that made the starter kick over continuously.  It did not start because the key was off.  The starter even tried starting with the kill switch on.  The only way I could get it to stop kicking over was to pull battery cable.  Next day it was fine.  I don’t get it?
Anyone have any ideas?  

It's possessed!!! I must say, that's a weird one. Not heard that before.  

I think it must have been crud in the starter switch which made it arch and cause a nuclear sub-atomic micro- injection python formation and organic mind reaction with the septic pump between the ears, which in tern made you scratch your head and wonder wassss up>  

Or the starter relay is corroded or got hot and stuck in the on position, but I like MFCINC's answer.