Apple MagSafe wireless charger grounding vibration

Hello,

I recently bought an Apple MagSafe wireless charger for my iPhone 14 pro. When the iPhone is charging (connected to the mains with a 20W usb-c adapter), when I run my finger gently over the charger (the rounded part) I feel like a vibration indicating that I'm following an electrostatic discharge of the passing current.

Is this normal and safe?

I, of course, cannot feel that vibration when everything is unplugged.

Thank you in advance for your answers.