Flickering lights are almost always an electrical issue, and the severity ranges from minor (a loose bulb or a single loose connection) to serious (a failing main breaker, faulty wiring, or overloaded circuits). If only one light flickers, start with the bulb and the fixture. If lights flicker throughout the house — especially when appliances kick on — you likely have a wiring, connection, or service issue that a licensed electrician should evaluate promptly.

Simple Causes to Rule Out First

Before calling an electrician, check the basics. A bulb that isn’t fully screwed in will flicker. A bulb at end of life does the same. LED bulbs paired with dimmers not rated for LED loads are a very common cause of flickering — the dimmer sends inconsistent voltage that the bulb can’t handle smoothly. If swapping the bulb or replacing an old dimmer with an LED-compatible model solves the problem, you’re done. If not, the issue is in the wiring or panel.

When It’s a Wiring or Connection Issue

  • Loose wire at the fixture or switch: Connections loosen over time, especially with thermal cycling. A loose neutral or hot wire causes intermittent contact and flickering.
  • Loose connection at the panel: A loose breaker connection or bus bar connection can cause voltage fluctuations that affect lights throughout the home.
  • Aluminum wiring: Many Denver-area homes built in the late 1960s and 1970s have aluminum branch circuit wiring, which oxidizes at connections and creates resistance — a known fire and flickering risk.
  • Overloaded circuit: When a large appliance (refrigerator, HVAC unit, washer) starts up, its motor draws a surge of current. If that surge causes lights on the same circuit to dim briefly, the circuit may be overloaded.

Flickering When Large Appliances Start

A brief, momentary dim when your air conditioner or refrigerator compressor kicks on is somewhat normal — motor startups draw a higher initial current. But if the flicker is pronounced, lasts more than a second or two, or affects lights throughout the house (not just one room), it points to a voltage drop issue. This could be an undersized service entrance, a failing utility connection at the meter, or a deteriorating main panel. These scenarios warrant an electrician visit and potentially a call to your utility company.

When Flickering Is a Warning Sign of Fire Risk

Flickering that is accompanied by buzzing sounds, burning smells, scorch marks around outlets or switches, or breakers that trip without explanation is a serious warning. Loose high-resistance connections can arc — generate heat and sparks inside walls — which is how house fires start. This is not a wait-and-see situation. If you notice any of these signs alongside flickering, turn off the affected circuits at the panel and call an electrician the same day. Done!’s team offers emergency electrical service for exactly these situations.

Colorado-Specific Factors

Denver and Aurora have a significant stock of homes built between 1960 and 1985, a period that overlaps with both aluminum wiring use and early-generation electrical panels that were later recalled or found to be problematic (Federal Pacific Stab-Lok and Zinsco panels are the most notable). If your home is from this era and you’re experiencing flickering, an electrical inspection is a worthwhile investment — both for safety and for your home’s insurability.

Flickering that persists after checking the obvious culprits should be evaluated by a licensed electrician. Done!’s team handles everything from a single loose connection to a full panel upgrade. You can also explore our outlets and switches services if the flickering is isolated to a specific room or circuit.