Board Thread:Questions and Answers/@comment-81.132.33.229-20121230140138/@comment-25546749-20121230155704

Redstone powers the block it is on and the adjacent blocks (even wires do that). Try placing some other block, say stone for simplicity, behind the lamp and then have the wires run on those. It will power the stone, the four stone touching that one, and the light behind it. Then the others won't light up and you can control it much more easily.