I have no idea, that's why I am asking.

I just drilled into some wood, a baseboard. The area is
nowhere near anything that could leak, it is a closet in a
corner of the upstairs house. After drilling, the wood in the
bit seemed wet. So I thought, maybe rain. But it smells like
turpentine, or something very similar.

An old house, but the addition is not that old (I think). I
really have no idea what it could could be.

For a few months, there was a canister of propane sitting in
that corner. But I am careful and doubt that it leaked
anything. Not that it would smell like turpentine anyway.

There isn't anything over there... And turpentine is volatile
so it would not stick around for years?

If somebody left a can of turpentine in the wall, certainly
it would smell? Seems weird to me.

Thanks.