That would be the 71st FG, 9th Army air core. The only P-61 FG in the ET.
414th Night Fighter Squadron, Twelfth Air Force. Received Black Widows in December 1944. Served in Algeria, Sardinia, Corsica, Italy, plus detachment to Belgium. Inactivated August 1947 and reformed as 319th All Weather Squadron.
415th Night Fighter Squadron, Twelfth Air Force. Received Black Widow in March 1945. Served in Italy, Corsica, France, Germany. Inactived September 1947.
416th Night Fighter Squadron, Twelfth Air Force. Received Black Widow in June 1945. Served in Italy, Corsica, France, Germany. Inactived November 1946 and redesignated 2nd Fighter Squadron (All Weather).
417th Night Fighter Squadron, Twelfth Air Force. Received Black Widow in April/May 1945. Served in Italy, Corsica, France, Germany. Inactived November 1946.
422nd Night Fighter Squadron, Ninth Air Force. Received Black Widow May 1944. Served in England, France, Belgium, Germany. Inactivated September 1945.
425th Night Fighter Squadron, Ninth Air Force. Served in England, France, and Germany. Inactivated August 1947.