I have humbucking pickups in my guitar, but I hear noise when I take my hand off the strings.
Humbucking pickups are designed to reduce low-frequency hum from the power lines at 50 - 60 hertz. However, there are often rooms with sources of noise at higher audio frequencies. This “hash” can be distinguished from “hum” by noting that it changes when you adjust your tone control, while line frequency “hum” hardly changes at all. Humbucking pickups do not completely eliminate this high frequency noise.