i think you just answered your own question there fella a pianfull tingle at 100v wont be an electric shock but static as you wouldn`t keep contact with the exposed metal part as if you had chances are you`d be dead or in quite a bad way
you may have had the static fault before earth to building was reinstated and as a result the charge wont have had a dissipation path so no tingle,reinstate the earth and hey presto you now do,looks like you had a combination of two problems which could have been much worse had the earth not been sorted
get an inspection mate to be sure