The Nail is an item in Pajama Sam in "No Need To Hide When It's Dark Outside".
Pajama Sam No Need To Hide When It's Dark Outside
Pajama Sam will need the hammer if he needs to get his mask from Darkness' living room. The nail is in the mines where the water meter is, however it is on a small island surrounded by lava, which makes it too dangerous for Sam to reach it by hand. After he obtains the magnet, Sam will need to use the magnet in order to get the nail off the island. Sam must then use the nail and the hammer from the abandoned shack in order to repair Chair back up (as one of his legs broke due to Sam's failed attempt to get the blue potion off the top of a shelf).