I went out of the house and I saw that the other houses had not got any lights, so it was not an electrical fault.

fault 是名词，意思是"故障、缺陷"，指设备或系统不能正常工作的状态。 electrical 是形容词，由名词 electricity（电）加上后缀 -al 构成，表示"与电有关的"。 electrical fault 指"电气故障"，即与电力系统相关的故障或问题。