Ground Faulc Circuit Interruptors.

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Is GFCI safer than a ground pin? Yes, in case a part of an appliance is not grounded. How a ground works - [1]. Also - just because there is a ground pin - it doesn't mean that it is connected or that it is connected properly.

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Can be wall outlets. $9.
GFCI circuit breakers also exist, but are expensive at $40 each - [2]
DIN Rail GFCI breaker - $5 - [3] - is this really GFCI?
Can be plug-in receptacles - [4]
Arc Fault Circuit Interruptors (AFCI) are another thing - [5]
Note that GFCI outlets sense differential current, and they are not grounded - [6]
Portable GFCI - GFCI on a power cord - [7]
A GFCI outlet is quite complex - with its own circuitry. See teardown and explanation - [8]
GFCI chip from On Semi - [9]