It depends with what you mean by 'dead', the truth is, in the new covenant, believers don't die but transition into life everlasting and their spirit indwells living believers where they both guide them and judge them. This is what the bible calls resurrection but no one understands it seems.
So i wouldn't say the living can talk to the dead but i can say the resurrected believers guide the living believers (together with Christ) but also judge them unto death if they continue going astray.
We see both Paul and Peter teach such:
2 Cor 4:
.
12So then, death is at work in us, but life is at work in you.
13And in keeping with what is written: “I believed, therefore I have spoken,”
c we who have the same spirit of faith also believe and therefore speak,
14knowing that the One who raised the Lord Jesus will also raise us with Jesus and present us with you in His presence.
15All this is for your benefit, so that the grace that is extending to more and more people may overflow in thanksgiving, to the glory of God.
2 Pet 1:
12Therefore, I will always remind you of these things, even though you know them and are established in the truth you now have.
13I think it is right to refresh your memory as long as I live in the tent of my body,
14since I know that it will soon be laid aside, as our Lord Jesus Christ has made clear to me.
15And I will make every effort to ensure that after my departure, you will be able to recall these things at all times.
A whole doctrine is developed from that verse in 2 Peter by the Catholics, the doctrine of asking the saints intercede.
I'm not saying that we should pray to the saints to intercede but it is biblical that the saints actually indwell us and somehow guide us.
Heb 12:
1 Therefore, since
we are surrounded by such a great cloud of witnesses, let us throw off every encumbrance and the sin that so easily entangles, and let us run with endurance the race set out for us.
The reason Paul used this argument for resurrection:
1 Cor 15:
29If these things are not so, what will those do who are baptized for the dead? If the dead are not raised at all, why are people baptized for them?