Oil level and reverse light switch

Can anyone please tell me if I remove the reversing light switch whether I should expect all the gearbox oil to drain out?
A couple of drops I am expecting.
The question is where is the normal level compared to the switch position in the side of the gearbox?

No. You can remove the switch without losing oil.👍

Be careful to test the new switch before you refit the engine cover etc. The switches usually need to be fitted with at least one washer as a spacer. The new switches are often supplied without a washer though and if they are just fitted as they are then the reversing light can stay on permanently. Save the original washer when removing the old switch. If you lose it or if you need a 2nd washer in there then they are exactly the same size as the sump plug washer (easy to get on Ebay)

Thank you both for the information much appreciated.
At present the existing switch tends to “fail closed”, i.e. the lights stay on.
That was not a problem before I changed the oil and cleaned the terminals when the lights tended not to work. It might have been failing for a while or possibly never set up right.
Just looking at the installation I’d say the switch has not been disturbed for a very long time. So probably failed.

While it's out does the switch still have continuity across the terminals? if not the switch is probably OK, and just needs packing out with a washer or 2.

Having never needed to change this switch, there is some smart information on here when the need arises, thanks chaps & bloke.
One observation following on from this; my car was built in 1998 & all the sensors are made by Elmwood.
I have changed the odd one, with mixed results, early on I noticed that the problematic devices derived their ground returns via the block & the replacements were little or no better than an original, however once the grounding surface was cleaned the original worked, arguably better than the unbranded replacement. Coincidence?
I’m now running on the original set. The brake light switch post dates the cars build but is an OEM device & having retrieved the original I repaired it.
M

A few years ago before I got the TF there was a feature about the reverse light switch on the F/TF in the MGOC magazine. These reverse switches were deemed unreliable and IIRC the common cause of failure was oil leaking past the seal and contaminating the terminals, I don't remember if the oil caused the contacts to stick or whether it conducted the power. The person who wrote the article  .tested  the switches from a number of suppliers and found that the majority were the same switch in different colour boxes but there were a couple of much better quality ones. I think that the MGOC supplied the better one, well they would wouldn't they

My reverse light switched has failed, but I haven’t got around to changing it as it’s not an MOT failure, only on cars manufactured after 1st September 2009.

I think it would be a MOT failure in my case as the car is showing white light to the rear all the time (well not all the time sometimes the switch works ok then at others it fails with contacts closed and lights on). Removing the bulbs temporarily resolves that in the short term.