What’s a polite way to tell someone it’s time to get the fuck out of your house?

Family: "Excuse me, I am having some bad memories right now... of ________ (most recently deceased relative). Sometimes I talk to ghosts all night long. It would probably be weird for you to see. Ghosts are real... I even saw ghost poo poo once."

Friends: "Alright guys I'm sorry but I need to be alone. Bad moods are infectious and no one here deserve it. I love you all, but need solitude NOW. When I am better again hopefully in a day or four you all will be the first gangsta ass hoes I call up."

"You guys are welcome to stay for the movie, highly recommended by my sexy French girlfriend."

(inserts Salo, or 120 Days of Sodomy)

Could also just literally shit in your pants without saying anything and just let the filthy smell creep in to the atmosphere... while emphatically denying it. The person or people will not actually want to "see" the mess; they'll leave instead.

Maybe next time the person or people bugging you is there, make a round of drinks but lace yours - if not all or others' - with exlax?

I usually stretch and yawn and say, "Well! Time flies! I didn't realize it had got so late!" Then I start picking up dishes and cans/bottles and taking them into the kitchen, making plenty of noise as I toss things into the recycling bin, clatter plates and glasses, put any remaining food away, and load the dishwasher.

I also stop offering any food or beverage refills about an hour before I want them to leave, and I'm usually out of any beverage but water by then--I keep enough in the fridge to be hospitable, and can re-stock from my secret stash in the pantry if I want them to stay longer. But what's in the fridge when they arrive is meant to run out before it gets really late.

Most people I know well enough to invite over either know what time to leave, or will get the hint when I first start shifting gears into GTFO-mode. If they're someone I don't know that well, or who is a slowpoke, I tell them (as I'm tidying up) how much I enjoyed having them over, and that we'll have to do it again soon, and maybe ask them about their plans for the following day.

It's all about getting them up and moving, and thinking about being somewhere else but on my couch.

I don't have a TV, so I don't have to deal with the inertia that sitting in front of the tube brings. But back when I did, I'd wait until just before the late news came on to get up and start moving around to clean up, and as soon as the opening credits came on I'd turn the TV off and say, "I really don't need to watch that stuff before going to bed; bad news can wait for tomorrow." That always got the point across.