But the line voltage prongs need to make solid contact with only the pressure of the magnet holding them in. The more gripping force, the more likely you'd trip on the cord. To me, that's the limiting factor.

A "trip sensor" like a garage door or safety table saw might have would add to the complexity.

I can check the code book, but there's a reason that plugs and outlets are snug, and you replace ones that aren't. A firm connection is a safe one.

NEC now requires Arc-Fault Circuit Interrupter. Wikipedia [0] says:

> An arc-fault circuit interrupter (AFCI) or arc-fault detection device (AFDD) is a circuit breaker that breaks the circuit when it detects the electric arcs that are a signature of loose connections in home wiring. Loose connections, which can develop over time, can sometimes become hot enough to ignite house fires. An AFCI selectively distinguishes between a harmless arc (incidental to normal operation of switches, plugs, and brushed motors), and a potentially dangerous arc (that can occur, for example, in a lamp cord which has a broken conductor).

> In Canada and the United States, AFCI breakers have been required by the electrical codes for circuits feeding electrical outlets in residential bedrooms since the beginning of the 21st century; the US National Electrical Code has required them to protect most residential outlets since 2014, and the Canadian Electrical Code has since 2015.

Reason for the code requirement: [1]

> Arc fault circuit breakers (AFCI) may still seem new to homeowners who haven’t dealt with electrical codes in a while. They’re the result of research in the industry on how home fires start and what might prevent them. Some studies reveal that electrical wiring issues account for over 150 home fires across the United States each day. An arc fault breaker differs from a GFCI outlet or circuit breaker in that it detects slow electrical leaks. A slow leak typically occurs when wiring is compromised but not completely shorted.

> A good example of this would be when a nail punctures a wire behind a wall and a small electrical current begins to build up heat. Another occurs when a wire nut loosens and a small arc allows the temperature to build between the wire and nearby ground. This can even happen when an outlet or switch connection becomes loose.

Quite possibly, arc fault breakers present the cheapest fire insurance you can give your home.

[0] https://en.wikipedia.org/wiki/Arc-fault_circuit_interrupter

[1] https://www.protoolreviews.com/what-is-arc-fault-circuit-bre...