First of all, this is not a transformer, but a special solid state control unit
that cannot simply be replaced with just a plug. doing so could result in
property damage and personal injury as well as being a fire hazard. Check
to see if this "transformer" has a fuse. Replace said fuse with a type of
same size and rating. Never, ever replace a transformer with a regular plug
on any electrical appliance! Doing so will cause property damage and
possible loss of life! I don't care what anyone else says, but always have
a lighted tree plugged into an outlet that can be turned on and off by a
switch on the wall, or an easily accessable power surge multiple outlet
strip. Also, have a dry chemical fire extinguisher that has been inspected
where it can be easily located in case of a fire. Be sure all of your smoke
detectors are working, as well. It would be a good idea to replace the light
set with a brand new one or a known good one ment for indoor use.
A final thought: do not listen to the advice from individuals who know very
little on the subject of electical equipment and / or electronics. I have a
lifetime of experience in all of these fields, and would only tell you what
you really need to know to help you and yours to be safe at all times.
Feel free to e-me. Happy Holidays!