Odpisuję na post sprzed 4 lat, ale jeśli nadal cię to interesuje, to wnętrze posiadłości było zbudowane w studiu.
But the mansion that we see in the film was largely built on sets. (...) Similarly, even the Whipstaff Manor left its mark and later also became the set for the filming of the popular Backstreet Boys’ music video for “Everybody (Backstreet’s Back)”. 
https://thecinemaholic.com/where-was-casper-1995-filmed/