Move sprite forever with random postion on screen

I tried to move random my sprites (the squares) but all sprite go to same position and ״vibrating״. What is the best way to move sprite forever and with random position?

//Make random shape
func makeShape () {

    //Check if have more than 12 shapes
    if shapesamount <= 4 {

        sprite = shape.copy() as! SKShapeNode
        sprite.name = "Shpae \(shapesamount)"

        shapes.addChild(sprite)

        shapesamount += 1

        moveRandom(node: sprite)
    }
}

//Move shape radmonly
func moveRandom (node: SKShapeNode) {

        move = SKAction.move(to: CGPoint(x:CGFloat.random(min: frame.minX, max: frame.maxX), y:CGFloat.random(min: frame.minY
            , max: frame.maxY)), duration: shapespeed)

        node.run(move)
}

override func update(_ currentTime: TimeInterval) {

    // Called before each frame is rendered
    if istouching && !isOver {
        let dt:CGFloat = 1.0/50.0
        let distance = CGVector(dx: touchpoint.x - circle.position.x, dy: touchpoint.y - circle.position.y)
        let velocity = CGVector(dx: distance.dx/dt, dy: distance.dy/dt)
        self.circle.physicsBody!.velocity = velocity
    }

    if isOver == false {
        for nodee in shapes.children {
            moveRandom(node: nodee as! SKShapeNode)
        }
    }
}

}

shapes is SKNode