If so, you are doing the same thing we Catholics do when we ask a saint to pray for us.
For further info, see the Book of Revelation, or Maccabees.
However, to answer your question....Yes, I have participated in many prayer threads. I believe that live people can pray, but I don't see how a dead one can. When one dies, one is no longer of this earth and I don't think they listen to prayers, or why they would be necessary to intermediate.
OK by me if you do. That is why we have a diverse religious community.
BTW, I know what Catholics mean by "saints", but to your really hard-core, mainstream Protestant traditionalists the saints remain dead in the ground (per various Biblical references). As a consequence, most really don't have a feel for what it is you are doing when you invoke a saint. BTW, Anglicans don't count in this ~ I think they have the same viewpoint on saints that the Pope does.