I am new to Arduino and physical computing When I measure the wire coming from any UNSET Arduino uno pin, the result is approximately 2 volts even the "ANALOG IN" pins. Considering that the pins which been set to HIGH and LOW are giving 5 and 0 volts "which is cool". Is that the nature of Arduino or is that a failure caused by short or anything else?
After a microcontroller reset, AVR IO pins default to input. In this state they have high impedance. For example, according to the Atmel ATmega328 spec sheet doc8271 Table 29-15, analog input impedance typically can be taken as 100 MΩ for design purposes. (Input pin impedance may in fact be orders of magnitude more, effectively an open circuit except for leakage currents of a few nanoamps.) Each pin has a few pF (5-10?) of capacitance [1,2,3,4] which in general is small compared to stray capacitances of attached wiring.
When stray electromagnetic fields charge the pin and stray capacitances, a small voltage develops on the pin. You could connect a 1 to 10 MΩ resistor between the pin and ground, to avoid the 2 V you are seeing.