LED Stair Light/LED Step Light

Step 2 Adding the 9v and Soldering the Switch

You want to avoid soldering anything DIRECTLY to a battery terminal. I found these snap-on battery leads online at a pretty low cost (see in picture). The leads come pre-stripped at the ends which make them pretty easy for soldering.

And now for the easiest step:

Attach the snap-on battery leads to the battery. :)
Once you've done this, feel free to 'test' away on those LEDs that you've already soldered. Simply hold one end to each end of the series of LEDs - you won't get shocked. This is also a fun way to figure out which end is your positive and which is your negative (the LEDs will only light up one of two ways). Try to keep track of which is which - you'll need to know which is the 'good' way once you start soldering on the battery and the switch.

Now for the sub-mini slide switch:
Despite being expensive as far as LEDs; I found that Radio Shack wasn't too bad so far as sub-mini switches go. There are a few other places online where you can look - up to you. I chose to go with a sub-mini slide switch that had two lead terminals (in the other picture) as opposed to three*.

*There's nothing wrong with having three leads. Just make sure when you're soldering that you're using either the 'first two' or 'last two' leads.

Now - go ahead and solder the tip of the red wire (coming out of the battery) to one of the leads. Then take the far end of the three, soldered LEDs (the end that made the LED's light up when the other end was touching the black wire) and solder it to the other lead of the switch.

Once this is done - you can go ahead and hold the other, unsoldered end of the three LEDs to the black lead from the battery and 'test' your switch. If you find that the LEDs don't light up - go ahead and double-check that you have them on there the right way. If you don't, no worries. Simply snip the end of the LEDs soldered onto the switch, flip them around, and resolder them starting with the other end.

If your LEDs are staying on no matter if you have the switch up or down, check to make sure that you didn't accidentally solder the two terminals of the switch together. Also, keeping a finger on both of the terminals at the same time causes a 'bridge' and may also be causing the LEDs to stay lit.