Reefer Madness?

John La Grou plugs smart power outlets

Various kinds of plugs and sockets are in use.

You were the better at rolling a reefer, I was the better at coke and rum Remember that night on the beach in Ibiza?

Those plugs are traditionally made of metal, but may be constructed from precast concrete, glass reinforced plastic or other composite material (especially in Europe, or where cover theft is of concern).

This is typically not a problem in most residential applications where standard wiring provides an active and neutral line for each appliance (that's why your power plugs always have at least two tongs) and the voltages are relatively low however these issues do limit the effectiveness of RCDs in other applications such as industry.