This is called ESD, electrostatic discharge.
silky or polyester clothes gets charged in dry weather and upon getting close to other objects gets discharged in a fraction of a second.
Try taking out your sweater swiftly in complete darkness. you will feel one on your nose...
the voltage can be thousands of volts but the duration is very very small, so not lethal.
I personally enjoy it but if you want to avoid the reflex of it, try a solid and quick contact or grip. Its usually the spark with its sound that panics you...