The answer to 'how to fix outlet installation' is to first turn off the power to the outlet at the circuit breaker. Then, use a voltage tester to confirm the power is off. Next, unscrew the outlet cover and the outlet itself, being careful not to damage the wiring. Inspect the wiring and connections, and make any necessary repairs or replacements. Once the wiring is secure, reinstall the outlet and cover, and turn the power back on to test the outlet.
It's important to take safety precautions when working with electrical systems, such as wearing rubber-soled shoes, using insulated tools, and turning off the power before beginning any work. If you're not comfortable working with electricity or the issue persists, it's best to call a licensed electrician to inspect and repair the outlet.