I took an interest in lucid dreaming a few years ago, and at the time I managed to have a few lucids. All of them were a bit short but their themes were far nicer. Now, I started lucid dreaming again around two months ago, after taking a large break and I've noticed a pattern. Every single lucid I've had (With a small exception of one) as had next to no light, as it takes place in my house during night with all of the lights turned off, or it takes place outside, nearly pitch black at night. I usually become lucid during random dreams with plots, but I always end up teleporting there. Not only does this often cause me to lose dream stability, but it dampens my dream control to an extreme. Last night I had a near-lucid nightmare, where I became lucid inside my house with all of the lights off and heard footsteps of a dream character. It was my sister questioning me about being awake. I had no idea what to really do, so I told her "Does it really matter?". After I tried to flip a few lights they came briefly on, very dimly, but as soon as I turned my attention off of them, they stopped making light. I know how expectation is extremely important for dream control, so I decided to expect other dream characters to turn the lights on. Sure enough it worked slightly, but I could still just barely see the rooms I was in. My sister then started trying to attack me by making rooms darker and covering me in blankets. I managed to glue her to a table using a complicated warding technique, and this helped only slightly. I then started getting really horrible and terrifying images of various things coming to life and attacking me. I knew it was a dream, and everything was made up, but that didn't change the fact that what I was experiencing felt real. Luckily enough nothing actually attacked me, but mostly because I woke up almost instantly. Now, one of the stranger things I find about this is the second I become lucid I teleport to a dark house, I can't even expect this, because it's RIGHT when I become lucid. My normal dreams are very rarely in places with little light though, making them far nicer.

Honestly, this is totally killing my motivation to lucid dream, as I find most of my lucid dreams actually effecting my mental state negatively.
I'm also aware that expectation of one thing to happen will cause it to, but I never started "expecting" my dreams to become like this. In fact, I only really started dwelling on this after having ten lucids in a row with the exact same outcome. I can't use this as a dream sign either, as this occurs ONLY when I've already become lucid.