I had an electrician wire my doorbell to my phone. When the doorbell is rung, the phone rings and I can talk to the person through an intercom system. If it was a florist, I would ask them to leave it at the door and when I saw his truck leave I could open the door and get the flowers.
Primary concern - stay safe! Don't take a chance.
My neighbor has a fake camera hooked up to the front porch. I found out by trying to let him know I had a package delivered to me for him. It was a weird feeling to see the camera pointing at me!