Electric shock from laptop
This subject pops up regularly. One reason is the rf filtering at the AC mains input of the power supply. The filtering tries to prevent the power supply polluting the electricity with high frequency switching pulses. The filter has often capacitors connected to the protective ground wire from both hot and neutral AC wires. The protective ground is directly or capacitively connected to the ground side of the DC output.
If you don't have AC outlet with proper protective ground - it can be nonexistent or have a voltage to your stone floor - you get an AC voltage between the DC output and the stone floor. If the protective GND is missing it's half of the mains AC voltage. It can be more if there's voltage between the protective ground and your floor.
I have seen how people destroy valuable electronics by using equipment which need grounded AC input without the protective ground. Sometimes they have tried to avoid ground loops which collect noise to their inter-device signals.
Finally there can be a fault. It can even be intentional. I guess you have a good possibility to get fake electronic devices if you happen to live in a place where businessmen can do what they want as long as local authorities and mobs get their part of the money. Or if you order something from a foreign webshop.
Stop using the system and let a proper electrician test your AC outlets and the device. Use only a person that you know he understands the problem and wants to solve it. He doesn't start &quot;it's only the low voltage DC&quot;.