Do these work in the Glade air freshener sprayer? Thanks!

Don' know. It depends on what size can the glade dispenser takes. The air wick cans are 8 3/8" high and 5 3/8" around. If your dispenser can accommodate that size then the air wick should work for you.

My spray unit has started making a creaking sound (think Halloween rusty coffin noise). Has this happened to anyone else? Any ideas to de-squeak it?

Change the batteries and put a fresh new can in. Lift the tiny latch all the way up to start a new spray cycle, click and close, put up and it should work perfectly!

Will the Air Wick freshmatic automatic spray air fresheners fit in the Lysol freshmatic automatic spray air fresheners units?

Thank you because the air wick device is cheaper and I had two Lysol refilly

Can you just spray it alone

Yes, I do that often - you can spray as much as you like that way. Also, the cans aren't quite empty when the auto sprayer quits so I use up the rest by spraying it myself.