According to the pilot of a Mooney M20F, he was flying a night instrument landing system (ILS) approach and became distracted while attempting to locate and tune in the airport's common traffic advisory frequency. The airplane subsequently descended below the glideslope and impacted the ground about 1 mile from the airport. The pilot stated that he did not experience any mechanical malfunctions with the airplane. He also indicated that due to strong headwinds, he had earlier stopped at an intermediate airport, and should have stayed there, as he was fatigued at the time of the accident. The pilot reported 1,075 hours of total flight experience, which included 990 hours in make and model, and 62 hours in actual instrument meteorological conditions. Weather, reported at an airport about 35 miles to the east of the accident site, about the time of the accident, included a visibility of 1.5 miles in light drizzle and mist, and broken and overcast cloud layers at 400 and 700 feet respectively.