The earliest you can get this is in the first act when you get to the lighthouse. Talk to James Stein and he will give you the side quest "Counsel of Despair." Have some decent weapons because there will be plenty of enemies while doing the quest. Upon completion talk to James again and he will give you the torch mod.
In order to build a torch mod you need:
-2 rags
-2 glue
-2 gas for lighter
-a stick, baton, baseball bat, ect.
Go to any workbench and create this mod and your achievement will unlock.