50 or so small lights flying in formation from NNE to SSWI was sitting on my roof watching the nightsky what I often do. I clearly know the diference between a star, planet, airplane or satelite. Then suddenly I saw many lights approaching from the NNE and moving in straight line to the SSW. I could only see them in the darker part above me because the lower horizons were too polluted by residential lighting. The only thing I saw were lights, I didn't see any shape that connected them. The amount of lights were somewhere between 40 and 70. The majority was shaped in a V-shape. Outside this V-shape there were also a few that formed a straight line. Then there were a few seemingly randomly spreaded around. There was no sound, also not after they had dissappeared for 5 minutes. The lights were white and if not for the moving they seemed just like stars. All the lights (V-shape, straight line and the randomly spreaded) didn't move relatively to each other. It seemed they were flying in formation. At first I thought they were many single objects. The next morning I realized that they could have been the lights of a single object. Because I don't have any clue of how far the lights were I also cannot say anything about the size of the object. If they were all connected the total shape was much larger then an airplane used for intercity flightsthat usually flies at 3 to 4 km height.Although I'm 100% conviced that this is pure coincidence the following is worth mentioning: After the lights dissapeared over the SSW there also entered a local airplane from the NNE which headed in the direction of W where the local airport of Taichung city is. This is quite normal because every 10 or 15 minutes one can spot one. Again the lights and the airplane were not observed at the same time. The airplane showed up after the lights had dissappeared.