I have never owned a Matchbox but I have a Matchbro and I did have a similar Goodrich device years ago so I am having a guess since no one else has replied. I would guess that You have to remove the casing to expose the innards and probably find one or perhaps two 9volt batteries which can easily be removed and replaced.
Hi Derek, You have to remove the fixing screw (see photos), the unit will come in two parts to gain access for replacing the 2 batteries/or wiring repairs. It's a simple job to do, good luck