So... Joria, have you ever seen that picture, you know, the picture on the thread where carl asks what the most devious things your sims have done is? It has a picture of him fencing in some sims and then lighting them, if you know what I mean. That's what you could do with the vampires, you could just get to know all the vampires in town, use the moveobjects on cheat to drag them into a little box, that has a furnace in it, the cheap one, it would be better if you could fit as many in there as you can without there being major pathing issues, don't be stingy with the rugs either.
![Wink ;)](https://www.carls-sims-4-guide.com/forum/Smileys/default/wink.gif)
Then use moveobjects on to drag your sim in there, cause a fire in all of the boxes,(how many that you have depends on how long it's been since you did your last "vampire cleanining") Then do the cheat that allows you to build when there's a fire, and move your sim out so she/he doesn't die with the vampires, if it doesn't work the first time, do it again, it's pretty fun to watch.
P.S:if your sim lives in an apartment, it wouldn't be the best idea to do this stragey, especially if your house has a lot of rugs.