Get the wood cut the wood to the correct size and sanded if
Drill 2 x 7.5mm holes at either end as show in fig 1.
Drill 2 x 5 mm holes near those.
Countersink the larger holes to about half way, so that you can
attach the nut of the 4mm terminals.
Insert the 4mm terminals in the larger holes, one of each
colour in either end, and secure with nut.
Attach the plastic bulb holder with the 2 screws, first
Cut a 6cm piece of each wire, strip the ends and solder onto
the tags on the plastic bulb holder. Ensure you have got red wire
to the red terminal and black wire going to the black terminal.
Then push the wire through the 5mm hole and out the other side so
you can then solder it onto the 4mm terminal.
It should look something like this. see fig 2. these are
usually very durable and can be used in conjuction with cell