Asking others to pray for you is certainly in Scripture. On the basis of Christ's intercession for believers, who is present at the Right hand of God (Romans 8:34 ;Hebrews 7:25), it is argued that other people who have died but are alive in Christ may be able to intercede on behalf of the petitioner(John 11:25; Romans 8:38–39. So much for the "not in Scripture" falsehood.
NOT dead people. You don't pray to them, and you don't commune with them. Period.
You want to go down that road, then you can live with the consequences.