I have one of those magnetic chargers for my phone , the type where you put an insert into the charging point on the device, they attach the charger by magnet. I never unplug the charger from the power socket - is there any danger in the magnetic end becoming attached to something else and "charging up" something random and then that giving me an electric shock?
Unsure I've come across those. Is that those which use an alternating magnetic field to induce a charging current in the mobile ?
But what sort of other thing do you think would charge up ? If not designed to use the charger why would it have an effect ? I can't see it being an issue. It'll charge things that are designed to use it.
All the device does is to create a low-voltage across two of the pins on the bit that plugs into your device, thus enabling it to charge your device. If it does get near anything else it cannot induce more than about 5 volts which will not harm you.
It's no more dangerous than leaving a PP9 battery lying around with the terminals uncovered; in fact it's less dangerous because it's less likely to be swallowed. Also it needs the circuitry in the bit that fits your device to actually generate the voltage.