Among the given options, the non-metal that is not a poor conductor of electricity is selenium (Option 2).

Non-metals, in general, are poor conductors of electricity because they do not possess the free electrons needed for the conduction of electric current. However, selenium is an exception to this rule due to its unique properties.

Selenium is a semiconductor, which means it exhibits intermediate conductivity between that of a conductor and an insulator. It has an interesting property called photoconductivity, where its electrical conductivity increases upon exposure to light. This property makes selenium useful in devices such as photovoltaic cells and light sensors.

On the other hand, let`s briefly discuss the other options to understand why they are considered poor conductors of electricity:

1. Sulphur (Option 1): Sulphur is a non-metal and a poor conductor of electricity. It is an insulator at room temperature and lacks the free electrons necessary for conducting electric current.

3. Bromine (Option 3): Bromine is also a non-metal and a poor conductor of electricity. It is a liquid at room temperature and does not have the necessary properties to conduct electricity effectively.

4. Phosphorus (Option 4): Phosphorus is a non-metal and a poor conductor of electricity. It is an insulator at room temperature and lacks the free electrons required for electrical conduction.

In conclusion, while sulphur, bromine, and phosphorus are all non-metals and poor conductors of electricity, selenium stands out as a non-metal with semiconductor properties, making it capable of conducting electricity under certain conditions.