I am replacing an old outdoor covered porch light fixture with a new LED fixture. The back of the new fixture plate is only about 1 inch max and needs to be flush with the existing wooden support block 6x9x 2" . The old light had a thicker back plate to accomodate a thin junction box. The new one does not. The wires come through a small 2 inch hole through the 2 inch thick wood support block which is mounted securely into the house's wood siding. I can secure the circular metal strap to the wooden block for mounting the light. Must I install a junction box? It would be a lot of trouble to get one recessed into the block.