Short answer: No.
Long answer: I have lots of information for you.
1. Find a Grave record: https://www.findagrave.com/memorial/136631241/_. This reveals that Enrichetto/Enrico also went by the name Americo.
2. Death record: https://www.familysearch.org/ark:/61903/3:1:3QS7-99H7-6QWY?cc=1935767&personaUrl=%2Fark%3A%2F61903%2F1%3A1%3AF8HK-9LX. This gives you information about his occupation (shoemaker) and his cause of death (carcinoma of the hard palate and jaw) as well as additional biographical information.
And finally, 3. 1940 census record. https://www.familysearch.org/ark:/61903/3:1:3QSQ-G9M1-KC1S?i=30&personaUrl=%2Fark%3A%2F61903%2F1%3A1%3AKSJ7-H7W. (Line 28.) At the time of the census, he was in the "State Hospital for Mental Diseases." Most importantly, however, his citizenship status is marked as "Al" - alien. Since this census was taken less than two months before his death, there is no chance that he could have become a citizen after the census. I can therefore say confidently that he was never naturalized.
Hopefully, some or all of this information is of use to you. I found all this using FamilySearch, which is a free genealogical website. It may be of some value to you if you have further inquiries. If I can help in any way, don't hesitate to ask. Happy research!
Hi Stephan Brigidi
Welcome to History Hub
I found a possible match to your Enrico Brigidi on familysearch.org. family search is a free website, you
just need to register to use.
Mr. Brigidi ill in hospital April 8 1940 Census marked AL means Alien not naturalized.
findagrave-passed May 31, 1940
His wife and children are also on the findagrave website.
Dear Mr. Brigidi,
Thank you for posting your request on History Hub!
Along with the information from the previous posters, we suggest that you request a certification of non-existence of a record of naturalization from USCIS (Genealogy Frequently Asked Questions - see About Further Research section), as well as submit an Index Search request to the USCIS Genealogy Program. USCIS should be able to provide the certification on non-existence, and although your grandfather will not have a naturalization record, it is likely that INS did create an A-File that could be used to verify his citizenship status.
We hope this is helpful. Best of luck with your family research!