No, I strongly urge you not to pursue this. Promises like this are usually false and do little more than take your money -- while deceiving you into thinking you've made contact with your loved one.
But there's another reason why I urge you not to pursue this: Such practices actually may bring us into contact with occult spiritual forces that are not from God, but from Satan. As such, they'll deceive us and harm us and cut us off from God. This is a very serious matter, and is the reason why the Bible commands us to avoid them. The Bible says, "Let no one be found among you... who is a medium or spiritist or who consults the dead" (Deuteronomy 18:10-11).
Instead, I urge you to turn to God and find your peace and comfort in Him. God loves you, and He knows the hurt and grief you feel. He wants to comfort you and give you hope -- and He will, as you turn to Jesus Christ and put your faith and trust in Him. When we know Christ, we know this world is not the end, but ahead of us is the joy of heaven.
Some day, your life -- like that of your late husband -- will be over. But in the meantime, make Christ the center of your life. The Bible's promise is true: "Weeping may remain for a night, but rejoicing comes in the morning" (Psalm 30:5).