Basically Electrical setup and don't for growing indoors.

Do and Don't with Electricity.

Do's

Indoors
1. Make sure you have proper wiring installed into your house and updated.
2. Proper extension cords at least 14/2 non-groundign 14/3 grounding.
3. Use surge protectors.
4. Clean extension cords with no cuts or wires popping outta the insulation. if so make sure to use the proper taping like Electrical Tape, or Tar type electrical tape that will mend to the extension cord well.
5. Make sure the no wires showing through or popping through the electrical tape.

Don't

Indoors

1. Not having your house wired up to date. this would cause grounding issues, the ground is based at your Electrical box that going to your meter outside.
2. Having bad Electrical Cords.
3. Anything that would cause fires around your growing system.
4. Don't use Duct Tape, it doesn't conduct electric well and possible electric shock to you or anybody else around you.
5. Water is a conductive solution so make sure when plugging into a outlet around plants you do not be standing into the water. (You will be grounding yourself out.)

Also I have done this with Recepticles that doesnt have grounding and you have a extension cord has one.. you can cut the ground off and use electrical tape to cover it, it works well, but i suggest to find a plug ground extender and take the screw out and screw it in the power plug box, at least it somewhat grounded.