No, Pathfinder has no rules about electricity conducting between multiple creatures
There is no general rule about electricity damage that affords it any kind of conductive property. If an effect has the potential to affect multiple targets, that's always explicit, either because it produces an area of effect or because it specifically describes affecting multiple targets. For instance, Chain Lightning has the target parameter:
Targets one primary target, plus one secondary target/level (each of which must be within 30 ft. of the primary target)
And Lightning Bolt says:
You release a powerful stroke of electrical energy that deals 1d6 points of electricity damage per caster level (maximum 10d6) to each creature within its area.
By contrast, the Electric Blast simple kinetic blast power of an Aerokineticist explicitly affects only a single target:
You shoot an arc of electricity to shock a single foe.
All of the simple kinetic blasts include some wording that specifies a single target. If you want an electric blast that does affect multiple targets, the Kineticist's rules offer a way to do it: modify your blast with the chain infusion, which allows you to daisy-chain the effect across multiple targets.
Realistically, electricity doesn't actually conduct very well through people; following a path of least resistance, it generally goes straight to the ground unless impeded by a decent insulator. The visual of an electrified puddle shocking anyone who comes into contact with it is a hollywood/videogame fantasy; the real danger of water around electricity is that most water is a somewhat better conductor of electricity than common materials, and so if you are wet or in water you present a more conductive path to ground than you otherwise would and are more likely to be struck by lightning/arcing electricity.
If your group wants to homebrew some new rules about how electricity damage works, that is of course up to you; it doesn't hurt so long as everyone is having fun. However, as you've seen, it will make using electricity-based attacks more complex, and that might end up being ultimately detrimental to your fun if your primary attack mode is an electric blast.