I have heard people mention the whole 'spirits/ghost' dwelling in a statue to receive offerings, but to be frank--why not just let them? The purpose of having an image is for devotion and to show respect towards the Buddha's and Bodhisattvas. If living beings can benefit from my offerings, then why not, right? Buddha's and Bodhisattva's don't sit there and gobble up our offerings, why not actually let a being that can benefit from offerings.. benefit from it? Remember the purpose to have an image of the Buddha or Bodhisattva is to inspire respect and devotion within the practitioner.
I have thought about that. I have also read stuff about it. A practitioner should strive to have the Buddha or Bodhisattva in his/her heart. The notion of the Dharma body should also be understood: it is everywhere. A statue or image of the Buddha or Bodhisattva serves as a reminder, which is really helpful for a beginner but maybe not as much for an experienced and ardent practitioner.
With the spirit/ghost dwelling in a statue or image to receive offerings, personally I prefer not to offer them the chance to do that. I do not want to encourage them to commit the act of taking what is not given. I would prefer them to use the statue or image in the proper way, that is, as a reminder and inspiration to practise Buddhism.
If I want to making offerings to spirits and ghosts, I would do it specifically with preta-dana practice, which I did in the past until my recent family incident.