Is it permissible to make a Chabad house/Jewish event in a hall that is run by the town called De La Salle Chapel? It looks like that in the early 1900 it was owned by a Catholic school. but no one really connects it to that.
The word “chapel” by definition is a place of christian worship, albeit sometimes in a more private setting that belongs to a parish in a town. Occasionally, it may refer to a non-denominational place of worship, but this meaning is not common here in the USA.
Therefore, if this is indeed the case, one may not use such a place for Davening or to host any other religious events, even if there are currently no religious/idolatrous symbols or pictures in the premises. The place may be used for other non-religious events.
If there were never any religious symbols at the location, one may use the place even for Davening or other Mitzvah matters, but only on a temporary basis.
ראה מג״א קנד, יז. א״ר שם טו. פמ״ג שם בא״א יז. שו״ת חת״ס או״ח סוסי׳ מב. משנ״ב שם מה ובבה״ל שם ד״ה נרות. וראה הנסמן בהמצו״ב בארוכה.