B757-200
Maintenance Airframe; Maintenance Powerplant
Communication Breakdown; Situational Awareness; Troubleshooting
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
General Flight Cancelled / Delayed; General Maintenance Action
Aircraft; Human Factors; Procedure
Inbound flight showing Logbook [item] # 3 on ACARS (Mid lavatory light inoperative for Mid lav).  We were expecting a simple re-lamp job.  What we found was the light lens bonded in place. After removing the lense; we pulled out the light assembly to find no wiring in place.  At this point; we started searching for the wires. We had to disassemble the overhead [ceiling] of the Lavatory module to find the wires hanging between the Galley module and the [inner] fuselage.  When I grabbed the wires to move them; I found them to be 'Hot' (Power on).  We killed [electrical] power to the plane and fished the wires through the conduit and        re-assembled the lights reference Wiring Diagram Manual (WDM) 33-26-21.  After reapplying [electrical] power; we checked lights and found lights to be operationally good.  We then reassembled aircraft and sent  the B757-200 aircraft on it's way. Not ETOPS.
A Line Mechanic reports finding a Mid lavatory (lav) light lens bonded in place and no electrical wiring attached. Further trouble shooting located the 'Hot' (power on); electrical wires hanging between the Galley module and the inner fuselage.