The answer to 'how to test outlet installation' is to use a voltage tester or circuit tester to check that the outlet is properly wired and providing the correct voltage. This involves inserting the tester into the outlet's slots to check for power, proper grounding, and any potential wiring issues.
It's recommended to test outlets periodically, especially in older homes or if you notice any issues with the outlet, such as flickering lights or appliances not working properly. Testing outlets is a relatively simple DIY task, but if you're not comfortable doing it or find any problems, it's best to call a licensed electrician to inspect and repair the outlet.