With the transition to site-wide HTTPS upcoming, it would be good to go through and check/fix any protocol-specific code on the wiki before it becomes a visible issue. I assume a fair amount could be fixed by bot, though there'll likely be cases that need hand-fixing.
Probably the most common issues are CSS imports specifically using HTTP (like @import url('http://dev.wikia.com/...
), 3rd-party scripts/iframes being loaded by JS, and API requests. Images being loaded via HTTP will work in both CSS and JS for most browsers (since they're considered display content) but it'd be good to update those too (where possible).