Parts related to a range hood do not require lubrication, according to RepairClinic.com. If the fan switch is stuck or noisy, either the internal parts need to be replaced or the filters require cleaning.
All of the related mechanical parts to the fan switch are permanently lubricated. Before diagnosing any issues, disconnect the power supply to the fan at the source to avoid electrical shock. The source could be an outlet or the fuse box. Check the filters in the range hood first. If the filters are dirty or greasy, they can impact the function of the fan switch and its internal parts.
Remove the fan filters. Soak the filters in very hot or boiling water. Include 1/4 cup of baking soda and a small amount of dish detergent. Allow the filter to soak for approximately 10 minutes. Use a non-abrasive scrub brush to clean the filters. Rinse the filters, and allow them to dry.
Reinstall the filters, and turn on the power supply. Test the fan switch by turning it on. If thoroughly cleaning the filters does not make the fan switch work, the fan motor, drive motor or exhaust fan motor of the range hood may need replacement. Lowe's suggests keeping the fan running the entire time of cooking to keep the kitchen less humid.