That's usually the kind of damage you see when something shorts out or a wire gets really really hot.
I'd fix that wiring before it gets worse.
is the one for the oil pressure sensor?
Hmmm.... make sure you have a good ground to both the engine and the body. The individual wires look like they got hot some how.....
ive been told that before, how do i go abouts doing that!? or do i have to take it to a mechanic?
The big fat ground wire (negative battery terminal) should go to a nice clean spot over by the starter on the engine block. Make sure there is no corrosion on the wire. (this usually isn't the problem)
Then make sure there is a big fat wire (10 ga or better) secured between the negative battery terminal and the body of the car (somewhere) once again make sure there is no rust or corrosion on any of the terminals. (I would suggest this is the problem)
Go buy new wires from your local auto parts supplier and replace what is there. Pretty simple to do with reasonably basic hand tools. If you are making any "custom" wires it is best to solder the ends so as to eliminate a corrosion problem in the future.