So here is a fun puzzle you can help me toy with: How would you make an ancestral altar complete with a home for them when you know nothing about your ancestors - save a bunch of the recent ones from an adoption were asses - and would like to make sure that altar is linked to your blood line so that not just any spirit could use it claiming to be related. Again I have no personal artifacts, few names, and very few photos for my Grand-mothers part of the family, no less from my grandfather's side and pretty sure there is nothing at all from my mother side at all.

A general offering "to the family" is not appropriate here - I don't think - I was told to look for one woman in particular who is several generations back of unknown relation to me.

I was thinking about using my blood in some way, but am unsure what principle would survive death. Perhaps a spirit house is not needed for contacting the lady and making general offerings but it is sticking in my mind for some reason.