Hello and happy thanksgiving to everyone

I was wondering if I can delete any unused files in the WoW directory? I got rid of the patch files, but I noticed there is a new folder in the data folder called "cache". was wondering if this is safe to delete or just leave everything as is? I have the intel value drive (37GB) and it is down to the last 10GB. I read if you have limited space on the SSD, it will cause performance issues in regards to speed.

thanks