I don't have a ready link of it, but most toy stores or big discount stores should carry this...

MegaBlocks (a lego compatible like toy) makes this Alien Agenda series of toys. The one I got (gag gift), is of Hangar 18. It goes together and looks like a complete hangar. Inside, it's got a little alien ship, little aliens and MIBs, an exam table, a containment tank, probe-like device, etc. It's just too funny, you just have to look at it the next time you're in the store.