Exit the room where you found the flashlight then turn left to find the red cable. The first door to the right has the switch but you have to reach it from the other side. One of the mentioned clippy/buggy spots is also located here, as marked below. To get past it, just move back and forth, or jump until you get through. Just follow the cable to the 2nd floor and it will lead you straight to the morgue.
Once you reach the morgue, there are four numbered doors here. Take note where the red cable goes; open that drawer and crawl inside until you reach the other end.
Achievement Unlocked: Open Up
Open all numbered drawers to unlock this achievement.
If you crawled into the wrong drawer, you’ll “fall” through a corridor and you’ll respawn outside the morgue door (thankfully).
If you crawled inside the correct drawer, you should see the bathroom in the other end, with the breaker in view. Operate it then backtrack following the red cable to the starting area.