Rep Power: 0

My car would sometimes go periods of time where it wouldnt crank but then it would start working again. Recently however it never turned on. I checked the starter so i knew that wasnt the issue and I just replaced the battery. So I checked the neutral safety switch. I removed the cover and it was dirty(where I work has a dirt road) I sprayed some cleaner and cleaned the cables and it started on and I havent had any issues since. But im unsure how that solved the issue? I didnt even open up the switch to clean it, just removed the cover and sprayed the surface and cables. Can anyone explain to me how that may have solved it?