If I remember correctly the neutral safety switch is a part of the gear change mechanism and is not repairable. A new/used gear change mechanism is required.
Liquids spilt on the gear change mechanism spells trouble.

Brake Transmission Shift Interlock
BTSI is a safety feature that enables the shift selector lever to stay locked in the Park position when the brake pedal is not depressed (ignition on) or when there is no current present in the Shift Lever Assembly. If the Shift Lever Assembly selector lever cannot be shifted from the Park position due to a mechanical or electrical failure, the selector lever can be released from the Park position using the shift lock override procedure. To do this, insert a long screwdriver into the notch just below the “-D+” symbol on the Shift Lever Assembly and depress the lock button while moving the selector lever out of the Park position at the same time. This will allow the shift lever to be manually moved out of the Park position in order to move the vehicle.