I believe they can see us and by the grace and blessing of God, He allows our loved ones and Saints to “drop” by, especially in a time when we are praying for help or in a situation where we need to have an intercession. I have had a rose delivered via a little boy who I never met, in fact he lived miles from me, the rose was from St. Therese who is very special in my life. Another time when I woke up in intensive care after what was suppose to be a simple procedure, the first few days I was alert as I could be and out of no where I heard my deceased twin brother telling me"Anna you will be alright, I know you hear me, God heard your prayers " So I had two instances where I received a message from heaven. I need not go any further than that. God Bless you..