Ah! Bridegroom Service.
Thanks. I think we've a thread here on that already.
Yeah, Wednesday night should have a service very similar to Tues, Mon, and Sun nights - a Matins for the next day.
Theoretically the Wednesday night service is not a "Bridegroom" or "Nymphios" service because the hymn "Behold the Bridegroom cometh," ("Idou o Nymphios erxete") isn't chanted, but rather a Troparion for the Supper and Arrest (which is done at the beginning of the chanting Thursday night also, after the Alleluias are chanted).
Otherwise, the format is similar: Alleluias, a hymn done three times, some Kathismata, Gospel reading, part of the Canon, Exapostelaria, Praises, Doxology, petitions, Aposticha, end (w/ prayer of St. Ephraim).
Our clergy Syndesmos of the Metropolis of Pittsburgh sells a book (done by Fr. Evagoras Constantinides) with the Matins of Thursday (i.e. the Wednesday night service).