Why do you think that the cable connection in house becomes dangerous during lightning?

Hint: Because the cable connection in the house can become dangerous in rainy days and also in lighting if the wiring and conduiting in the house is not under proper fixing and lighting falls on the house. Plumbing pipes, gas pips and other electrical heavy cables open in many houses and also are not fixed in the proper way. By that can the short circuit in cables and also can current flow from any electrical device if those are rust.

Complete answer:
Lighting is the electric spark in huge amounts between clouds. Charges in motion occur in the conduction of electricity.
Lighting is a large discharge of static electricity within or near a thunderstorm. Generally stroke of light within the clouds occurs about 80% and stroke of light within the clouds and the ground occurs about 20%. The stroke occurs as lumps of positive and negative charge develop. The charge means adding and subtracting electrons to create an ion. Such as; Positive Charge – Less electron and negative charge – more electron. Electrons move by physical stripped and by temperature difference.
The lighting stroke begins when the electric field exceeds breakdown voltage. The start and stop of lighting in steps progresses towards ground, called the stepped leader. It is very faint and essential invisible to the human eyes.

Note: When the stepped leader gets near the ground, positive charge moves from the ground up toward the stepped leader. That is called streamers. The streamers may come from almost any object on the ground. Such as: Trees, Antennas, Grass, poles etc.
We generally use a lightning rod or lighting conductor to protect from lightning strikes in our houses.