There is no communication between us and the deceased persons. Hadeeth says: The deceased is too far from the living person while the living person is too close to the deceased ( very near to die). ما أبعد الميت من الحي وأقرب الحي من الميت.
Some very pious servants of Allah can under certain circumstances communicate with certain deceased person if there is a religious necessity, but this is not available to public.
Such pious servants of Allah do not come up in public and never claim anything. You need to be careful from those who claim to attract people's attention of benefits.