Ask the Mauritians
What better way to get help with your queries than to ask the localsJoin Community
Where can I get a mask of Barack Obama?
If you can't get it, make one yourself :p
We don't really celebrate Halloween here, so I doubt you'd get this mask in local shops, lol.
Like @moricien said, your best bet is eBay/amazon or other shops on the internet, most probably abroad.