Induced voltage problem?

[Fungus82]

Hi guys am a first time poster so be gentle .

I have an induced voltage of 70v on the faceplate of a control unit on an extract fan I am working on. I have taken the plate off and there is an earth cable from the plate going on to the circuit board on back of plate. But there is no earth from the terminal on the circuit board going back to the power box. Is this the reason I am getting induced voltage??

 

[Spark123]

If it isn't earthed then it is reasonable that you can get a tingle or a belt from it.
Can you post up piccys? Industrial, commercial, domestic?

 

[Fungus82]

It is an industrial toilet extract fan single phase motor with 2 fans. Can not post photos. And on front casing is 2 boxes. 1 is the fan controller. This is where I am getting 70 volts from. I have taken covers off of both cases and there are no obvious defects. All I noticed was that there was no earth from the first box ( which has main earth terminal ) and the second box

 

[ban-all-sheds]

Is this in a commercial/industrial environment, i.e. a place of work?