rear shock squeaking

Perhaps it's some sand/dust/debris that gathered between the rear spring and lever?
Maybe you can get rid of it by using an air compressor?

Is it the shock or could it be the swing arm mounts? Try wd40.

You probably don't want to hear this but I've just had the rear shock replaced under warranty......it didn't squeak but had a sound like there was loose metal floating around inside.....and it developed over nite......

Best of luck finding the issue.

Don't use WD40. It will leave a mess after it dries out. WD40 is good a loosening rusty bolts and removing water from wet fastners. That is all.
Try a PTFE based dry lube like LPS. You and your bike will be much happier.