If you have a wobbly ceiling fan, it is probably rooted in one of two problems. First, turn off the fan and check to see that it is securely fastened to the ceiling. If you see loose screws, tighten them and then make sure the junction box cannot be easily moved when you shake it. Turn on the fan again and see if these lose screws were causing the wobble. If the fan still shakes, the problem is usually unbalanced or warped blades. To test for unbalanced blades, attach a clothespin about halfway down one of the blades and then turn the fan back on to see if the clothespin's weight balanced out the wobble. If not, keep trying each blade to see if additional weight keeps the fan steady. When you find such a blade or blades, glue one or two coins to the top of that blade and test it again to see if the wobble goes away. Add more coins as needed. If the clothespin doesn't do the trick, then you will have to remove the blades with a screwdriver and pliers. Place each of the blades on a flat surface and check to see that they align with the flat surface. If they don't, they are warped. In this scenario, you'll need to buy a replacement blade. Bring the old blade with you so you can purchase the right combination of length and weight. Then reinstall each of the blades and enjoy you're newly stable ceiling fan!