So today we received a letter with a used plaster in it. That was it. We moved about 5 months ago, so not that many people know our new address and we don’t know anyone from near the area of the sorting office (South East Anglia). We don’t recognise the handwriting, and our surname is spelt incorrectly.
Any ideas?
That’s bizarre. 
Sounds like a booze thread gag.
A bit plastered
The plaster is also in its original plaster packet (the rip open ones) so not sure it can be accidental.
Someone’s having a laugh at your expense…
Possibly - tbh I don’t think I know anyone who would do that - certainly not someone who knows my address (and I don’t know their handwriting).
Who was in the place before you just forward it onto them and see what they do with it it may end up in tbe Philipines or Poland 
The other question that needs to be asked is why when you moved did you not tell anybody your address?
Where were you in 1984? This is obviously from Bob Geldof who has been sending out promotional letters in this fashion for the last 37 years.
You’ve only just got yours.
We did, but people we’d know wouldn’t get my surname wrong.
How difficult is it to spell Saint?
You can’t send diseased items by email.
Probably from a disgruntled local who just happen to be on holiday in East Anglia.
Shouldn’t have bought the house they wanted for one of their offspring 
It’s probably the Masons.
Sticking plaster for a Tory
Perhaps the silent implied threat of a not very serious assault? 
Depends.
If your surname is Walker and they’ve spelt it Wanker then it may be an intentional mistake.
What did you get? Godlard? 
Godard…
Well, reading between the lines, it sounds like you’ve potentially annoyed someone who has gone out of their way to find out who you are, probably heard it spoken out loud rather than written it down.
When I was working in NI I lived in a town of about 10k people. A lot of people I didn’t know from Adam knew who I was.
Welcome to country living I suppose. Idyllic, init.
Know your target. 