These tiny wasp/flies have been invading my house recently. I usually find at least 1 every other day.
Here's a photo with a measurement (7mm) from head to end of gaster:
They are actually quite a bit larger than that due to their long legs and extremely long antennae. Their antennae are actually longer than their body, as you can see here:
My initial guess was some sort of spider wasp, but I find it odd that I would be finding so many considering they are solitary creatures.