I have the TMCC version of the Culvert Loader and Culvert Unloader. They work great. However the light in the house only comes on when there's a train where the culverts get loaded/unloaded. I'd like to add some lamps onto or around the station. I will want to connect them to the power already coming to the accessory. I know many have done something similar. Can you recommend a light to use? I did it for the icing station, a goose neck lamp, and it doesn't stay in its place very well.
For realism, I guess goose neck lamps attached to the shed is preferable to free standing light posts?
Well, there's a whole lot of options out there, and it's really a matter of selecting the option that best matches the esthetic of your layout and your lighting needs. For instance, Charlie's DIY spotlights are not only inexpensive but match well with a postwar toy train esthetic IMHO, even though they're not too close to any particular prototype. You can purchase gooseneck lamps from Western Scenic as part of their "Just Plug" product line, which are good if you'd prefer to use plug in components and avoid soldering. BTW, problems with securing the added lighting fixture can usually be solved with a strategic dab of hot glue IME!
One of the "go to" methods for adding area and building illumination are LEDs, available in both strip and bulb form. You'll need to match the voltage and current requirements with the available power source, but there are many inexpensive ways to provide and regulate that power at need. One of my "go to" light sources has been a batch of small (3mm IIRC) warm white LEDs with incorporated resistor that will operate on accessory voltage, AC or DC. They can be used inside buildings, as sign spotlights, or under a shed porch roof, to name a few uses I've come up for them. Here's a couple I used inside transparent tube sections atop two columns in a trolley station on the el track (a couple of LED street lights are also visible in the park behind and below the station in the background):