Replacing an outlet: back-wire clamps, not backstabs, and the 5 mistakes I see

Backstab holes (push-in, spring) loosen with heat cycles and are the number one cause of warm outlets and flickering. Use the screw terminals or, better, a "back-wire" receptacle with clamp plates under the screws.

1. Hot (black) to brass screws, neutral (white) to silver, ground (bare/green) to green. Hook wires clockwise so tightening the screw pulls them in.
2. Pigtail if more than one cable is in the box; do not use the outlet as a splice point for the downstream run.
3. Torque matters: snug plus a quarter turn. Loose = heat.
4. Fold the wires in an S so they do not shove the outlet crooked.
5. Replace with tamper-resistant (TR) outlets; code has required them since 2008 and they stop forks.

15 amp outlets are fine on a 20 amp circuit if there is more than one outlet on it. A single-outlet 20 amp circuit needs a 20 amp (T-slot) receptacle.