"erdschlussfrei" simply means "ground fault-free", but "faradisation" is a kind of electrical muscle stimulation so I think Casey is on the right track.

I, too, think its a "quack" machine. A device made ca 1920s was offered as a miracle cure for whatever the peddler thought he could sell. It was designed to deliver mild electrical shocks. The plug on the power cord and nomenclature indicates this is European. Similar contraptions were made in the US as well. My father-in-law had one that he cannibalized to make shocker for his bird feeder. It was rigged so that he could energize it by a push button in his house.

Thank you everyone. Yes, I noticed "faradisation" and it sounds a bit strange cause the circuit seems more that of a morse machinery ( and this could explain the presence of the big bulb light ). I tried to search on internet faradisation machines but they appears quite different...so I don't know but you could be right cause that bobine could be a faradic bobine.

I don't know what this is, but the link below shows the parts of one stored in a custom box.
http://www.invaluable.com/auction-lot/vintage-faradisation-by-erdschlussfrei-295-c-119d62e3b1

The device is a Faradisation made by Erdschlussfrei.

I have a hunch that the the name of this device refers to Mr. Faraday. He the one who formulated the mathematical relationship by experiment between the voltage generated in a winding when the winding is in a changing magnetic field. This effect is named, Faraday's Law. One common application of this effect is the spark coil for ignition in automobile engines.

It is possible that your box is a demonstrator for lab use to teach and/or measure the effect. More research is needed to identify the device. This opens a new avenue.

Photos of details, particularly of the coils and working parts and connection terminals on top of this box may be helpful. There seems to be some kind of adjustment wheel in the works.

I found this:
Source: on-line dictionary by Babylon 10

Definition of Faradisation

Babylon English

stimulation of muscles or nerves by means of electrical currents, treatment by faradism (also faradization)

This definition puts us back to a medical treatment device.

Faradization:

The URL below takes you to a study of faradization on patients afflicted with malarial fever (AKA intermittent Fever). This work was reported in 1884.

https://books.google.com/books?id=rUWgAAAAMAAJ&pg=PA219&lpg=PA219&dq=faradisation&source=bl&ots=ozAE5GGacC&sig=iO75HgrYebCn9dWi3v9Q-ZyykCk&hl=en&sa=X&ei=J8okVcuHMsWdsAWJnoDQAg&ved=0CEkQ6AEwCA#v=onepage&q=faradisation&f=false

The results were mixed. Faradaization was stopped on several subjects in the faradization-only group and quinine administered.

I think the study was flawed because there was not a group who received no treatment. There was no way to find out if those who improved in the faradaiation-only group would have improved anyway without faradization.

One site placed the estimated bid price between $50 to $70. This may reflect the market, but in my opinion, it is too low. It may that low if the buyer and seller does not know anything about the machine's history, the number available, or its cloudy history in medical treatment.

Your device has an incandescent bulb mounted on it. If this type of lamp was originally included on the machine, it helps to bracket when it was made. It would have to be after the Edison light bulb came into general use.