Strange goings on with the electrics

[VINTAGE...@gmail.com]

My 84 was not run much over winter. its not garaged. When I came to
start it the battery was nearly flat, recharged the battery car
started no problem.
Ran around in it to blow the cobwebs out.
A couple of days later same thing happened battery had gone flat, did
the same again recharged battery.
Third time, I assumed it was the battery giving up so installed new
battery, problem came back!
In the mean time windscreen wipers developed an intermittent fault
would stop centre screen and then stop and start all over the place.
Some other aux also stopped and started.
I assumed bad earth, No they all checked out ok.
At first all electrics SEEMED ok, however we discovered all the AUX
electrics were live with the ignition off?
The heater fan was running constantly at a very low rpm.
Ignition switch off, windows worked, heater fan works, the only way of
turning every thing off was disconnecting the Battery.
Looked at fused board nothing obvious, gave it a dose of silicone
spray didn’t do it?
Now I’m at a loss as to just what’s going on.
Could it be the ignition switch has fallen apart in side? So aux work
all the time and only when you key it does the ignition works?
We found no power to the Windscreen wipers so that got a new feed, and
as for the heater fan we had to disconnect it.
I have to make sure I leave nothing switched on as its all still live
but that doesn’t help a few days and the battery is flat.
Anybody else had this sot of problem, or might be able to throw some
light on to just whats going on?

Thanks Peter