I hate sticking my hand into a dark mailbox to look for my mail at night. We have big spiders in the neighborhood. So instead of buying a mailbox light, I thought of making one when I came across a solar path light at the 99 cent store.
Step 1: Get a solar path light
Buy the solar path light at 99 cent store or get a more expensive one from Walmart or Home Depot. The cheaper the better since you are only using the electronics.
Step 2: Take the electronics out
Take apart the light and carefully remove the solar cell, battery and circuitry. Be careful not to damage any wiring or the solar cell. Since the plastic housing was glued together, I used a pair of diagonal pliers and simply cut it apart to remove the electronics.
Step 3: Install circuit into your mailbox
My mailbox has a plastic top that was removeable with screws. I simply used double-sided foam tape to stick the solar cell to the sun facing side of the mailbox and the circuit board to the inside wall. Make sure to stick the solar cell on the side that has the most sun during the day. If your mailbox top is not removeable, you may have to desolder the solar cell from the circuit, drill a hole in your mailbox for the wire and resolder the wire.
Step 4: Done
Here is a picture of the inside of my mailbox at night. It is bright enough to easily see any letters may have in the box at night. The light should work for many hours after the sun goes down.