Hello,
Sorry for the confusion is 80 volts earth and neutral.
Just a guess your multimeter was set on auto scale and you read 80 mV (millivolts). Not 80 volts.
Look to the right of the measured 80 do you see mV? 80 mV?
While using the multimeter you might want do some measuring. Check for the HOT to neutral contacts AC line voltage at the outlet as well as for the correct Hot/neutral AC polarity
1) Insert one meter test probe in the HOT, small blade slot, and the other in the neutral, larger blade slot. You should measure 120V nominal. (Somewhere around 120V)
2) Check for the correct Hot/neutral AC polarity. Insert one meter test probe in the HOT, small blade slot, and the other test probe in the equipment ground hole contact. Make sure you are making a good connection on both contacts. If polarity is correct you will measure 120V nominal. (This will also tell you have an equipment ground.)
.