Lucas rear brake light switch grease?

[Tigerfeet]

I've opened up and cleaned out the original Lucas rear brake light switch, and it is now working perfectly. Before I crimp it back up, I am tempted to pack it with grease - just ordinary general purpose automotive stuff.  Does anyone know if that is what they would have done originally - or whether it is a good - or bad idea?  There was some ancient residue in there - but I've no idea what it had been.

[neil1964]

Suggest you put contact (dielectric) grease rather than normal grease.
https://www.ebay.co.uk/itm/364182151018?var=0&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338268676&toolid=10044&customid=CjwKCAjwm_SzBhAsEiwAXE2Cv-HRoL0TPmj8tjirTgg5YO-kjyxOHJ-oT_m4_5MTa-eryAqR5zgOfBoCjfQQAvD_BwE
Ideally when you finish your build use this inside each bullet and spade connector and on your chassis grounds etc. 
It will save lots of grief later if you intend using the bike in all weathers.

[Rog1]

I haven't used dielectric grease before, (I had to look it up) but like normal grease it does not conduct electricity; don't pack the switch with any kind of grease because it'll stop working.

Here's some info on the grease linked to in neil1964's comment:

https://www.permatex.com/products/lubricants/speciality-lubricants/permatex-dielectric-tune-up-grease-33-oz/

[Mike40M]

Dielectric grease purpose is to protect from corrosion. Contact surfaces must be kept clean from it. Vaseline works as a dielectric grease. Still used in small quantities to lubricate cam in points and magneto ignitions.
The older 7 pole trailer connections is prone to failure. Usually every other year. I've used CRC 5-56 for decades to restore function. Then OK for another year or two. Gives some corrosion protection. Also used it for handlebar switches without the hassle to take them apart. Think 5-56 is what I had used for your brake switch.

[neil1964]

Yes you still need a good mechanical metal to metal connection but you put it around the inlets and around the joints.  I use it on my motorcycles and my Series Landrover where corroded bullets have become a thing of the past.

[AltcarBob]

You can use plumbers silicone grease it's the same as the grease in the link but if you go to a proper builders merchant you should get a small tube for a lot less.