slight leak on 4wd switch thingy!

After my recent MOT and service, the mechanic commented on a slight oil leak where the 4wd switch(?) is mounted on some housing underneath. He said not urgent and was probably a quick swap over if I wanted it doing. All box oils were clean and full so he just mentioned it.

So can anyone suggest what it is called properly, what it does and do I need to attend to it?

I realise as I type this, some of you might suspect my technical knowledge could be written on the back of a postage stamp with a hot poker, and you may be right! So I can get more technical words off him if needed.

Thanks in advance.

Can't be 100% sure as the age of your Jimny will change things and my comment is based on the term "switch", but I would suggest its the transfer box solenoid, but its a guess to be honest.
This only applies if you have push button 4wd selection.
Best you can do is have a look yourself underneath and take a picture of any potential oil leaks. Having said that if its not leaving oil on your yard I would not call it a leak and would ignore it.

Thanks. It's a 2001 with a manual 4wd selector.
I got the impression it was the bit that detected that 4wd had been engaged, and illuminated the bit on the dashboard.
It doesn't drip that I have noticed, and all oil levels were good... sometimes it's the little things that die quietly that cause the most trouble, so I thought I would ask.
Cheers