There is a big switch on the FLOOR when you go down the rope. It is nearly impossible to see because you are standing on top of it.
Go to the bottom file cabinet and open it. Go down the stairs in the cabinet, turn on the light switch (by your feet) get the bell clapper that hangs near the ceiling.
I am guessing you are talking about Big Nate Island when you are in Detention. Well, it is VERY simlple. You click on the second drawer on the file cabinet. Very simple.
You leave him in the hideout
You have to use your stink bomb you made in the science room.Then the women will leave the room.Go to the cabinet click on the bottom of the cabinet and it will open.
what island? just look up a written walkthrough for whatever island you are stuck on.
In the file cabinet, in detention, in the school.
If you mean the bell clapper, you'll need the fart bomb. When you put the fart bomb in the dentention room, the teacher will go out the door. Then go towards to the file cabinet, inside the file cabinet, it'll be dark, so you'll need to find the power switch. (It will be harder to find the power switch if you have a computer that shows dark color) Then, you'll find the bell clapper!
a guy who was trapped there!
The difference between a cherry file cabinet and a normal file cabinet is the finish of the wood. Cherry file cabinets have a deep brownish-red finish.
You go to the file cabinet and click on it and it will take you somewhere under, switch on the light and find the bell part, you don't need to ask the guy ther anything unless you want to customize.
The stink bomb gets the teacher out of your way, and you can click on the file cabinet, which opens the door to the secret room (the light switch is at the bottom). At some point, you must go to Nate's locker and open it, to get the blueprint showing the secret room. (see related question)
Set off the stink bomb and enter the file cabinet.