My kenmore electric makes a very loud humming noise like a fan is hitting something

SOURCE: washing machine will not spin makes loud humming noise

motor coupling needs to be replaced

SOURCE: loud humming noise

If all of your door switches check out, replace the magnatron, capacitor, and diodes.

SOURCE: GE Spacemaker XL1800(JVM1850CF001) - Loud Humming noise

You either have a bad magnetron tube (5 or 10 year parts warranty item through GE Factory Service 1-800-432-2737 or www.geappliances.com) or a shorted high voltage rectifier. I think the light being out is a secondary problem.

SOURCE: Freezer Fan making humming noise until Turbo Cool is pushed - GE

yes need to replace

SOURCE: Cooling fan motor is making loud humming noise

You will have to pull out the light engine. That will consist of 4 or more screws and disconnecting some plugs. The the whole unit slides out where you can get to the fan housing.

Unless you're mechanically inclined, you should not try it as you could damage the assembly.

I don't know the part number off hand and some of those have newer part numbers as replacement for the original. Just do a google search to come up with a part number.