Flickering lights are one of the most common electrical complaints, and the cause ranges from harmless to genuinely worth investigating.
A loose globe or a failing LED driver is the simplest explanation, and it's isolated to one light. Try re-seating or replacing the globe first.
Not all LED globes are compatible with older dimmer switches, which can cause flickering or buzzing. Swapping to LED-compatible dimmers usually fixes this.
If flickering affects a whole room or several lights at once, a loose connection at the switch, light fitting or switchboard is a likely cause, and this is a job for a licensed electrician rather than a DIY fix.
Lights dimming briefly when a large appliance (like an air conditioner or oven) switches on can point to a circuit that's carrying more than it comfortably should.
Flickering that's widespread, gets worse over time, or comes with warm switch plates or a burning smell should be checked promptly rather than left.