Wwi swiss army helmet?

It does not have much value, primarily because there are numerous like it out there. The only thing that would give it value is original ownership. Who owned it and who was he? If the owner was a notable figure and wore this particular helmet on a significant occasion, then it will have value. Of course, you need to have the supporting doents and papers, supporting this. Otherwise, it literally has no value and you can easily find numerous like it in minor antique shops throughout Switzerland and even Austria.