I think I answered your post on this question on another thread, but in case it was missed or not registered here it is for you, just be sure this came through eBay messages and addresses you by your real name, not your username ID. Never click on any links in emails.
Others too, have received similar 'warning emails', and no further explanation to which item is involved, very frustrating.
All I can suggest if you have made several purchases recently, and not sure to which this refers to, is to contact eBay Customer Services, for them to explain further.
The easiest and quickest way to contact Customer Services is through this link, for a Call Back .
https://www.ebay.co.uk/help/eua?id=5275&mkevt=1&mkpid
On weekdays lines open between 8 a.m. and 10 p.m. - 6 p.m.
Weekends lines open between 9 a.m. to 6p.m.
If they cannot provide more information all you're left with, is to contact the manfacturer's of recent purchases, ask if their product you purchased has been recalled for safety reasons.
@ianrc2000