Hi

so this movie is from the late 80’s or early 90’s. in colour, english language and video format

its about a brother and sister who live in an apartment building (i think they had just moved there). the sister gets kidnapped by some monster/demon thing that lives in the building. the brother, with help from an old lady (who turns out to be a witch), tries to rescue his sister.

please help me name this movie, i’m becoming slightly obsessed by it.