This joke has been done 50 (yes, 50) years ago by my father-in-law.
First, a little background:
He lived in a small village, north-west of Quebec City along the St-Laurent
river. In those days, toilets were located outside the house in what
we call in good ol' french canadian 'becosse', from 'back house' I think.
These are a little wood shack with no floor over a hole in the ground
where you ... You can guess.
Now, for the joke:
He and a friend were thrown out of a party by the doorman.
When it was really dark,, the doorman went to investigate what was
knocking at the window. They had suspended a rock to the window
frame so it hung right it the middle and tied another string
to the rock and hid behind the 'becosse' where they pulled
that second string to make the rock knock in the window.
That's an old trick. The doorman wouldn't fall for that one. So
he followed the second string in the dark
and soon concluded that they were hidding behind the 'becosse'.
He ran toward the merely visible wood structure...
But my father-in-law and his friend had taken care of moving the
shack six feet ... Boy he fell in the shit !!