We've been dealing with WCK's fear of "monsters" at bedtime for a long time. Every night, I get out a spray bottle filled with a tiny amount of "scary spray". The spray contains a secret ingredient that only monsters can smell, and they find the smell revolting so they stay away. (Secret ingredient = tap water) We spray the spray over all of the common monster hiding places: the closet, under the bed, etc., but WCK still believes the monsters will get past the spray somehow. Perhaps they have gas masks. I'm not sure.
So then I remind her that if any monster tries to get into the house, I will kick it in the butt. This worked well for a while, but then WCK started finding loopholes. "What if it's Jabba the Hutt? He doesn't have a butt!" and so on.
Then I started giving a speech about how, no matter what, no matter the state of the monster's buttlessness, I would never, ever, ever, ever, ever, ever, ever, ever, ever, ever, ever, ever, ever, ever, ever, ever, EVER let a monster into our house. Ever. It doesn't seem to matter how many "evers" I put in there. WCK remains cynical about my monster-beating-up abilities.
Finally, last week, in exasperation, I told her that if she could bring me proof of an actual, live monster in her room, I would pay her five thousand dollars.
For a while, she was coming out of her room with random dinosaur toys, trying to convince me that they were monsters so she could cash in. I told her I would only pay the reward for a real monster, and he needed to be captured alive.
Now she's torn. She really doesn't want a monster in her room, but she really, really wants that money. It's a Catch-22.