But I think that's a misleading way to frame the issue. The central question of meta-ethics is not about the world and whether it contains entities of a special sort. Instead, it concerns our practical reasoning, and whether some answers to normative ethical questions ('What am I to do?' 'How to live?') are better than others. So we do best to approach meta-ethics from an epistemic, rather than ontic, angle.
Put most simply, the question is whether our moral judgments can be improved. There's nothing particularly 'spooky' about answering in the affirmative. On the contrary, it seems entirely plausible that my evaluative beliefs (just like the rest of my beliefs) are not as coherent and unified as they possibly could be. My idealized self would see room for improvement -- inconsistencies to iron out, etc. So we can make sense of there being a gap here between belief and truth, i.e. between what my actual moral views are, and what they ought to be -- what they would be if I were to reflect more carefully.
So, don't worry about whether moral entities "exist". We don't need any such things in order to secure the kind of objectivity or 'moral realism' that matters. All we need is for there to be more or less reasonable answers that could be given to moral questions. As I like to say:
Philosophical truth just is the ideal limit of a priori inquiry; it does not answer to the sort of independent reality that might sensibly be considered beyond all epistemic reach. Whereas physical facts are made true by existing things in the world, philosophical facts are made true simply by the fact that they are what ideally rational agents would believe.