So a large client of mine gave me access to their Organisation GitHub account.
With it came a login for myself (on github.companyname.com) and of course access to certain repos on their company account (by switching the user to the company via the button in the top left).
Now I was wondering, since I can create private repos for myself, is it safe for me to use these for non-related projects or can the company administrators access my user's repos despite being private? My understanding of Github is limited as it is, so this extra layer of complexity from the organisation account isn't helping too much.
UPDATE: Thanks to all of you who posted answers and wrote comments, all were really helpful. I have decided to no host any personal projects on their enterprise account as suggested, and again, as recommended I now host my repos on a private provider like bitbucket.