FBI house

An FBI house is a normal-looking residential house that is owned and occupied by
FBI agents, usually two of them who are partners, and which is used to spy-upon a
targetted individual on a long-term basis.
FBI houses can often be recognized by their bright external lights on the
front of the house, which are on all night.
Such lights serve to give a better image to their cameras,
which are used to watch the targetted person leave or return-to their house.
Oftentimes there are two or more of such houses in the vicinity of a targetted person's house,
so as to get more-thorough views thereof.
Sometimes the FBI will dip-into their budget and build a two-story house,
so as to better see-into a targetted person's backyard.
Your tax-dollars at work.

Watching the person leaving and returning is the most basic function of such houses,
but hardly the only one.
Knowing when a targetted person is away from their house is essential for
knowing when to execute secret "sneak-and-peak" warrants.
Such houses can also serve as locations of "tempest" equipment which can see
the content of computer-screens, television-screens, and smartphone-screens through walls,
via radio-frequency emissions therefrom.
-And that is not the only spy-technology that the FBI can use
while using such a house as a base.