~36 volts on Neutral  Ground
If you measure 36 volts between neutral and earth and ostensibly 240 volts between live and neutral AND live and earth then clearly this means that 36 volts is close to 90 degrees phase shifted from the 240 volts.

This is because if the two voltages were in phase you would measure: -


240 volts between Live and Neutral AND
240 volts +/- 36 volts between Live and earth


Clearly this isn't happening because you measure 240 volts to neutral or to earth and this largely happens when the earth-neutral voltage is 90 degrees phase shifted to neutral-live.

When this happens, mathematically, instead of simply adding/subtracting 36 volts and 240 volts together to get 276 volts or 204 volts you do a vector/phasor add like this: -

$$\sqrt{240^2+36^2} = 243$$

Another way is looking at it like this: -



In other words you are measuring about 240 volts in either scenario even though there is 36 volts between earth and neutral. This is typically due to a break in the earth line and, what remains of the earth line connected to your socket, is capacitively coupling to live and neutral to the tune of 36 volts. That waveform of voltage will be 90 degrees out of phase hence the imperfect fit with normal additive mathematics.