The missing fuse will spawn randomly in one of 3 locations:

• Infirmary:
  On the ground near the desk
  
  
• Workshop:
  On the ground between one of the wood stacks and supply cabinets
  
  
• Canteen
  On the floor between the tables

The "special spices" are located at the edge of one of the tables in the kitchen

There is no way to access the warden's profile before you reach level 13 and a certain plot event occures.
Spoiler:
You will gain access to the warden's PC through a hacking kit that you will acquire from one of the prisoners during the "White business" quest.
Once you're on the warden's desktop, the file you need in order to advance the plot is a map of our prison with a secret room marked on it. The file is named "nothing_at_all" and is located in the recycle bin

"Search the morgue to find the secret passage"
In the morgue find the "Morgue Safety" poster to the left of the supply cabinet. Behind it there will be a pin-code panel. Notice how only one digit looks used and worn - that is the only clue you need to crack the code.
Solution: 1111
After entering the correct code the cabinet will slide over revealing a secret entrance.