Well, I mean actively act, after the dead person died.  If I were to, say, act, talk, or make excuses after I was dead, that would make me a pretty amazing spy, wouldn't it?
I'm not that good.  I'm just a dead guy.  Six feet under the walk of fame.  That's who I am. Not a spy that's pretending to be dead. I don't know who put that idea into your head.