If you notice a constant drip in your home, it is very likely from a water line. If this is the case, shut your water off. Typically, your water shut off is located inside your home near the hot water tank on or around your water meter. You may have noticed that there are individual water shut offs in your home, however it is best to simply turn off the main valve.
In some cases, a drain or water line in the ceiling or wall could be the source of the leak, meaning the area may only be wet on occasion. However, mold begins to form in damp areas after 12 hours, so it is important to repair the problem right away.