所谓漏电，就是线路的某一个地方因为某种原因（自然原因或人为原因，如风吹雨打、潮湿、高温、碰压、划破、磨擦、腐蚀等）使电线的绝缘或支架材料的绝缘能力下降，导致电线与电线之间（通过损坏的绝缘、支架等）、导线与大地之间（电线通过水泥墙壁的钢筋、马口铁皮等）有一部分电流通过，这种现象就是漏电。 当漏电发生时，漏泄的电流在流入大地途中，如遇电阻较大的部位时，会产生局部高温，致使附近的可燃物着火，从而引起火灾。此外，在漏电点产生的漏电火花，同样也会引起火灾。
The so-called leakage, the line is a place for some reason (natural or man-made causes, such as wind and rain, humidity, temperature, pressure, cut, touch friction, corrosion etc.) the insulation capability of wire insulation or scaffold material between the wire and the wire leads to decreased (by insulation, support damage etc.), and between the ground wire (wire reinforced by cement walls, tin etc.) there is a part of this phenomenon is the leakage current through. When the leakage occurs, the leakage current will generate partial high temperature when it enters the earth's way, if the resistance is greater, causing the nearby combustibles to catch fire and cause the fire. In addition, the leakage of electricity generated at the leakage point also causes a fire.