It's important to know which country this is in because colour codes vary.
In common house wiring, black is the power wire, white is the neutral, and green is the ground wire.
You don't say "turn off" or turn on". Light should be connected black to black and white to white and ground to ground. If you connect white to ground it will work, but you are then using the ground wire for an unintended purpose. Neutral is bonded to Ground at the panel. Current on ground wire could cause ground loops and may cause GFCI to trip if you have them in your house.
To answer this question fully the type of appliance has to be stated and its voltage.
Ground
I am guessing that your 3 wires are black (hot), white (neutral) and bare or green wire (ground). Connect black to black, white to white and ground wire to the metal case of swag kit.
In common house wiring, black is the power wire, white is the neutral, and green is the ground wire.
You don't say "turn off" or turn on". Light should be connected black to black and white to white and ground to ground. If you connect white to ground it will work, but you are then using the ground wire for an unintended purpose. Neutral is bonded to Ground at the panel. Current on ground wire could cause ground loops and may cause GFCI to trip if you have them in your house.
No.
To answer this question fully the type of appliance has to be stated and its voltage.
No, the white should be approximately zero and the black approximately 110-120, assuming the "bare ground" refers to a bare conductor attached to electrical ground.
Ground
from salt white to coal black
The bald-faced hornet is a black and white hornet that you can find hovering close to the ground. These hornets are common across the United States.
I am guessing that your 3 wires are black (hot), white (neutral) and bare or green wire (ground). Connect black to black, white to white and ground wire to the metal case of swag kit.
If you are connecting 120 volts, you connect the black wire to the breaker, white wire to the neutral bar, and ground wire to the ground bar. If you are connecting 240 volts connect the black & white wires to the breaker, & ground wire to the ground bar.
Only ground
hoverfly