The electrical interface protecting apparatus is coupled between the wall-outlet and connected equipment to solve the difficulty of keeping broadband over power line modems and connected equipment safe from lightning and power surges while at the same time functioning effectively. The apparatus includes a low pass filter to prevent symmetrical signals from being attenuated and also an electromagnetic interference filter to provide clean and safe power at another outlet while preventing noise generated by connected equipment from being injected into the power line. It also provides a grounding means which reduces the leakage current flowing into the earth ground.