The answer to the above question is: “Sometimes no and sometimes yes.” Lights in your house that start to flicker can indicate minor issues you can correct yourself or which an electrician can fix, but aren’t a source of major worry—except for losing light in a few bulbs.
On the other hand, flickering lights can warn that there are bigger electrical faults in the house, some potentially dangerous. These problems absolutely require a professional electrician to repair. Never attempt to do any wiring or panel repair on your own, since it can create larger fire hazards and a high danger of electrical shocks.