Notes

Why does electricity go to the ground wire and not through you if you are also standing on the ground?
Electricity returns to the low potential side of its source, through a path commonly called ground. To get there it flows through all available paths proportional to the impedance of the path in relation to all other paths. The path of lowest impedance isn’t always obvious or what we intuitively think it should be, but in this case it is clear. You pose a larger impedance to ground than the wire does - so the electricity will flow throw the wire.

An unused electrical outlet is a source of potential energy, If nothing is plugged into the outlet, no power is being consumed. The same is true if a device is plugged into the outlet but is not turned on. Consider a DC battery that is not in use. The battery stores energy. If a flashlight is not turned on, no energy is being consumed. Batteries do decay over time when not is use. Power in batteries is a chemical process and they do not hold a charge indefinately.

Is current always emitting from a socket even when no device is connected?
No,,, for current to flow, there must be a complete circuit and that circuit is not complete until something is plugged into the outlet and turned on.


If the electrical system in your home is working correctly, then touching a ground wire shouldn’t give you an electric shock. Ground wires are a backup plan or fail safe designed to limit or reduce the chance of electrical fires or shocks.
If, however, there is a break in the main circuit, then it is not safe to touch the ground wires. In this situation, the ground wire will be carrying the electricity to the grounding bar.
If, however, there is a break in the main circuit, then it is not safe to touch the ground wires. In this situation, the ground wire will be carrying the electricity to the grounding bar.
Sometimes, you can’t see or know whether electricity is using the ground wire, which is why it’s best not to touch any kind of electrical wires. If you need to do maintenance, the smart thing to do is kill the power to that circuit with your circuit breakers.

As usual a lot of the comments from uneducated repeaters saying the myth (amps kill you, not volts). This is like a common thing uneducated people say, unsure who originally started that saying.
However you need both voltage and current to kill you, in fact neither of these can exist on their own, electricity flow is a product of both of these measures. Current doesn’t exist without some voltage also, and voltage cannot exist unless there is current also.
For all intents and purposes in real life, you should be looking for high voltage to be what is dangerous, because virtually every high voltage source you will ever come across, will easily have enough current to kill you. It’s the voltage BTW that allows the electricity to flow through you body.
To make a simple analogy, voltage is kind of like the pressure, and the current is kind of like the volume.
This is why a 12v battery can output huge current, but it needs big thick wires to do this (huge volume), but the 12v battery doesn’t have the voltage (pressure) to penetrate your body.
However high voltage has far more pressure, and thus it only needs thinner wires as the pressure makes up for volume. 
For example in power, 100v at 1a, is equivalent to 10v at 10a. 
Both are 100w, because the power is simply calculated by voltage x current (amps).
The point is, despite low voltage sources being able to output massive current, they are totally harmless to you, because they don’t have enough voltage to overcome the resistance of your body to allow electricity to pass through you body. Therefore giant current at lower voltages can’t do anything to you.
It’s when voltage starts to get above 48v mark that you should treat it as potentially deadly. Because at this voltage, it has a possible chance at being able to overcome the resistance of your skin and allowing current to flow into your body and kill you (especially if your skin is wet). 48v is the maximum where something is considered low voltage, it’s still considered dangerous, for example if you prick your finger on the 48v wire and it goes into your skin (gaining direct contact with your blood), it can then electrocute you. 
The point is don’t handle anything within that range with your bare hands, especially never hold two opposing contacts in either of your hands at the same time (circuit then goes through your hearts and can kill you very quickly).
Remember, as long as there is enough voltage (pressure) for the electricity to enter your body, it only takes a tiny something like 20–30 milliamps of current to equal enough power to kill you (meaning yes, a mere 1.5–2w of power can kill you).
Be safe, don’t handle anything that is high voltage, it’s deadly and marked as such for a reason (despite some people online who don’t know what they are talking about and want to tell you about voltage being safe and only amps killing you), they don’t know what they are talking about.

Where does the electricity go after it leaves whatever device you're powering via a wall socket?

The electric current that “goes out” on one wire “goes in” on the other wire. Electric current can only flow in a complete circuit loop.
What does “leave” the wall socket go to the device is energy at some level of power. Power is how fast the energy is transferred to the device.
The electrical energy supplied by the wall outlet leaves the circuit inside the device where it is turned in to sound, light, mechanical energy (as in running a motor), radio signals and/or heat depending on what the device does with it.
Th best analogy I have is that of a bicycle chain. The chain goes around in a complete “circuit”, but it is the motion of the chain that transfers the energy. from pedals to the wheel.