My grandpa worked as the gardener in the biggest cemetery in my state for about 16 years.
One day as he was working, he saw a pile of things that were to be thrown out - and in the pile were two really ornate flower vases that looked really expensive. They were intact, save for a few chips. Growing up in a poor village in Europe, he hated seeing people throw usable things away, so he decided to take them home. He left them out in the garden overnight.
The next day was his day off, so he spent it working in our garden and tending to our animals (chickens, ducks). He says that around midday, he looked down at his hands and noticed that they were covered in blood that looked like it was coming from between his fingers. He assumed that he'd hurt himself without noticing, even though it was a LOT of blood & there was no evidence of blood on the tools he was using. He's one of those old men that drinks coffee at the same heat as fresh lava, and has been set on fire twice while he was in the army, so he didn't think too much of not noticing that he was bleeding a fuckton. So, he went to go and wash it off, but it wouldn't scrub off, no matter what he did. He also says that this is when he noticed that the blood wasn't dried - rather, he was still bleeding.
Worried, he showed my grandma, who's extremely superstitions & was a nun for a good 5 or so years, who promptly lost her shit when she noticed the vases he'd brought home from work. She berated him into taking them back to work, which he did that afternoon. He says that next time he looked at his hands, there was no trace of blood on them at all.