A strong electrical smell developed in the aft galley of a B767-300 in cruise at FL370. Turning the utility bus switches off apparently solved the problem. An emergency was declared prior to landing because of an unusual noise in the galley.

Narrative

We were notified by the Flight Attendants in the aft galley about a grinding noise followed by a strong electrical smell in the aft galley area. We turned off the utility bus switches to cutoff power to the galleys; then almost immediately were told by them that the smell started to dissipate after they turned off the chillers. (Not sure which action was performed first.) I asked the Relief First Officer to go back and investigate. He reported that there was some smell but was 'going away.' We looked at our checklists; closest checklist I could find was galley smoke/fire (even though we had no smoke or fire); which says to turn off the utility bus switches. A couple minutes later I asked them if there was any more electrical smell as a follow-up. They said; 'completely gone.' As we started our descent for landing; aft galley Flight Attendant called again; and said there was a grinding noise coming from the aft galley floor area. At this time we as a crew decided to declare an emergency to obtain priority handling from ATC to get the airplane on the ground without any undue delay. (They normally give us holding followed by extended radar vectors at lower altitudes for spacing into ZZZZ). I told the Chief Purser that we would be making a normal landing; but to expect fire trucks around the airplane; and the Relief First Officer would make a PA announcement to passengers so that they would not be alarmed. After landing; fire crew inspected the tail section; did not see anything abnormal. We taxied to our gate without any problems. Chief Purser said that without electrical power; the First Class and Business Class passengers could not bring their seats upright for landing. We decided to not turn the utility bus switches back on and risk electrical fire. It was very busy since it all happened just as we started our descent after an all-nighter; but we worked pretty well together as a crew.