There's only one bishop left consecrated during the TIME of Pope Pius XII, and he's 104 years old.
http://www.catholic-hierarchy.org/bishop/bpinc.html

He was not, however, consecrated by Pius XII himself.

+Pearce sounds like another mythical bishop like +Pintonello.  +Pintonello refused to sign any of the V2 docuмents.  We have no indication that +Pearce rejected Vatican II or whether he was just missing for whatever reason (didn't feel like going to Rome?).  Nobody ever heard of +Pearce working for the restoration of the Church, or whether he gave any formal approval to this group, or just wrote a polite e-mail back saying "sounds nice."  It's easy to claim that +Pearce approved them since he died 5 years ago.

See, he's a "PURE" bishop because he didn't sign Vatican II (vs. +Lefebvre, etc.).  And, unlike these others who have no connection with the pre-Vatican II jurisdiction, see this man was consecrated by Pius XII.

PS ... there's no living bishop I could find that was consecrated by Pius XII.

https://dioceseofprovidence.org/most-reverend-george-h-pearce-sm-dd

According to his diocese, we have the following:

Retired Bishop, Archbishop Emeritus of Suva
“Maria Spes Nostra” (“Mary Our Hope”)
Died August 30, 2015
More in the Rhode Island Catholic, 09.10.15 – Archbishop Pearce remembered for his spirit, devotion
Archbishop Pearce was born in Boston, Massachusetts, on January 9, 1921, son of the late George H. and Marie L. (Duval) Pearce, Sr., he attended St. Columbkille School in Brighton, Massachusetts, and Maryvale Seminary in Bedford, Massachusetts. In preparation for the priesthood, he studied at the Marist College and Seminary in Framingham, Massachusetts. He was ordained a priest on February 3, 1947, by Archbishop Richard J. Cushing at Our Lady of Victories Church in Boston, Massachusetts.
Father Pearce was a secondary school teacher at the Marist Fathers’ Preparatory Seminary in Bedford, Massachusetts, from 1947-48, and at St. Mary’s High School in Van Buren, Maine from 1948-1949. From 1949-1956, he was a missionary in the Samoa Islands (South Pacific). In February 1956, he was appointed Vicar Apostolic of the Islands of Samoa and Tokelau and ordained a bishop on June 29, 1956, in Boston, Massachusetts. In June 1966, Bishop Pearce was appointed the first Bishop of the Diocese of Apia (Samoa), and in June 1967, he was transferred to the Metropolitan See as Archbishop of Suva (Fiji Islands). In 1969, he also served as administrator of the Diocese of Agana (Guam and the Marianas Islands), and from 1969 to 1971, he was the first President of the Pacific Conference of Catholic Bishops (CEPAC).
Archbishop Pearce participated in the four eight-week sessions of the Second Vatican Council in Rome from 1962-1965 and was one of the last living Council Fathers. In October 1969, he also participated in the First Extraordinary Assembly of the Synod of Bishops in Rome. In April 1976, he resigned from the Metropolitan See of Suva (Fiji Islands) as archbishop emeritus and returned to the United States. From 1977 to 1979, he served as a member of the Core Group of Bethany House of Intercession at Warwick Neck, Rhode Island, and from 1979 to 1983, at its location at Hastings-on-Hudson, New York. From 1983 until 1997, he was a personal assistant to Bishop Louis E. Gelineau and was in residence at the Cathedral of SS. Peter and Paul in Providence. In recent years, he continued to help with Confirmations and other pontifical ceremonies in the Diocese of Providence. He was very active in the charismatic and pro-life movements, and on April 15, 1999, he received a pro-life award at the Pro-Life Conference held at the Inn at the Crossings in Warwick, Rhode Island. In recent years, he resided at Saint Antoine Residence, North Smithfield.

I don’t think this is the bishop they are talking about. There is another alleged bishop who is alive right now.

Well, this link claims that there's a living bishop consecrated by Pius XII (not Pearce).

Since the death of Archbishop Pearce, the Sisters have been blessed to be working with one of the few living Bishops consecrated by His Holiness, Pope Pius XII Himself.

There's no bishop alive that anyone could find who was consecrated by Pope Piux XII (Bishop Pacelli).  Even if there was some bishop who was consecrated in 1958 at the age of 30, he'd be 92.  After being elected to the papacy, I absolutely doubt that Pope Pius XII would have been anything other than the PRINCIPAL consecrator, and catholic-hierarchy does not list him as the principal consecrator of anyone still alive.

http://www.catholic-hierarchy.org/bishop/bpacelli.html

Here's a link to the Catholic hierarchy site listing the bishops consecrated by bishop Pacelli / Pius XII as principle consecrator. 

Unlike many others, I have met the Italian Bishop in question. I have seen his papers and they are legit with was seal 1958. I have met Reverend Mother Marie De Montfort and she is an honest woman. I have questioned some of the things that the Catholic Research Institute has published and then later found out that it is accurate. As to Father James Kosik he tends to pick and choose what his Bishops say. So prayers for you and your parish.

ICR was most recently working with Bp. Dominik Kalata, who was consecrated clandestinely in Eastern Europe during communist persecution. He died last year, though. Such bishops do exist, although there are very few (and soon there will be none, I suspect). But groups like ICR, as well as people like Abbe Belmont (with whom Kalata also worked), have a knack for finding them.

Does this mystery PiusXII-Bishop know the Nigerian Prince whose email somehow ended up in my Junk Mail bin?