Mojjax,
While you so close to the motor bearings while rewiring power cords and switches, try something that has worked great for me. On motor bearings that are not damaged or have not overheated and started to come apart, I use an old Vet syringe and draw directly from a quart bottle of motor additive called "Dura Lube". If you'll soak the bearings as much as you can, spin the fan/motor shaft, then add a bit more, the bearings will last far past any other problem you'll have....
I oil my bath vent fans' bearings, the top and bottom "sealed for life" bearings of my outside A/C compressor unit's cooling fan, bearings for my foreign made 8" dual stone grinder, my Ole-Tyme Hunter ceiling fans that have the 2 oz. oil reservoir,+ and any sleeve or ball bearing I can get oil into. I also use it in my lawn equipment engines and on the chipper bearings of a 10hp chipper/shredder, as well as my V-8 F-150.... ;>)
Bill