I some times take things, but it's situational, I don't explore homes often, feels strange to me routing through personal things, even if they are dead or moved on, just not my thing but if I do I'll 100% not take anything.
I enjoy underground stuff, military stuff and any old engineering like trains and such, in these places I never take anything that I would consider an artifact, but every mine/cave I do I always take some pretty rock back with me ( got a fucking house full of rocks and fossils )
On military sites or old egineering sites,if I happen upon an old bullet or interesting bit of iron/bolt/pin that is in some undergrowth or to the wayside, and it not bolted/fixed into place I don't feel bad taking it.