I use these from Amazon. Not the bulb that comes with it, just the fixture. You can link them together if you need more than 1. They are easy to hang from chain.
https://www.amazon.com/dp/B00AKKUBDQ/?tag=exoticpetnetw-20
Do you have a bottom on your outdoor enclosure? My Boris has dug out a couple of times! I think I need to rebuild and put in a floor so he cannot escape via burrowing - he is a big time digger!!