Electric Traps and a High-Tech Marker

You are lost deep in an enormous maze.

The maze is made of rooms, automatic sliding doors, and fluorescent-lit hallways. The maze is so large and uniform-looking, and your memory is so bad, that you aren't able to remember where you've been or how you got wherever you happen to be. Rooms are connected by hallways with doors at both ends. Hallways can have stairs and ladders to other stories of the maze. There is exactly one exit.

Halfway through every hallway, the walls, floor, and ceiling are lined by strange metal. Every time you step on the metal, the hairs on your arms stand up and you hear a high-pitched squealing coming from the walls. The squealing continues until you're off the metal on one side or another. If you come back to a hallway and step on the same metal a second time, you hear the squealing again, but even higher-pitched. If you step on the metal in any hallway a third time, you get electrocuted and killed. There is no way to get through a hallway without stepping on the metal.

You find in your pocket a high-tech marker that can only write on the metal walls in the hallways, and only when they're squealing. You have no other way to leave markings in the maze.

How do you find your way out alive?