What cause power fluctuations in the home I get occasional flickers of brightness as if a small surge is present. Is it caused internally or externally?

Lights in a home can flicker when the voltage received at the light is not staying stable. Two main causes: >the starting of machines or appliances with motors (like a refrigerator) and/or heating elements (like a laser printer)- the voltage dips when motors start, thus causing the lights to blink slightly. If even the smallest machines cause flickering, then the size of the wiring in the building may be too small. This is not dangerous but annoying. >Loose or arcing wire connections - this could be inside or outside the home. If outside it would be loose connections on the utilities companies wiring, and make the whole house flicker. If inside it would be somewhere in the house's wiring. **Arcing is a hazardous condition that can start fires.**