The answer to 'why is my GFCI outlet flickering lights' is that a flickering or blinking GFCI outlet is often a sign of an electrical issue that needs to be addressed. This can be caused by a few common problems, such as a faulty GFCI, a wiring issue, or a problem with the electrical load connected to the GFCI.
Some of the most common causes include: a tripped GFCI breaker, a loose or damaged GFCI outlet, too many devices plugged into the GFCI circuit, or a short circuit in the wiring. The flickering lights are the GFCI's way of indicating there is a problem that needs to be investigated and resolved for safety reasons.