In what way are gravitational and electrical forces similar?

Another difference between the two forces is the fact that gravitation only attracts, while electrical forces attract when the electrical charges are opposite and repel if the charges are similar. Thus, gravitation is considered a mono-pole force, while electrostatics is a dipole force.

The similarities are

Both gravitational and electric fields have field strength that also follows the inverse square law in relation to distance. Mass or charge in a gravitational field/electric field has potential. Both of these forces use the product of masses or charges between them and both of these forces are inversely proportional to the square of distances between them.