Installing outdoor sensor light -- Did I do something very bad?

Excuse me if my terminology is wrong:
I started a project installing an outdoor sensor light.
I had a 1 flicker light switch in my basement which controls a light bulb in the cieling. With help, I installed a second flicker light switch so now there are 2 nobs and a new plate. The idea is 1 to control the existing light bulb, and the other to cut power to the outdoor sensor light.
In the cieling, we tried "stealing" power from the light fixture in the cieling. Supposeably my helping partner knew what they were doing. We almost had it setup correctly, however we had an accident. The fuse/switch on the panel was not turned off, and we saw some sparks fly when 2 wires touched (I dont know what wires they were). This tripped the switch on the panel and turned it all off. My question: Can this damange anything in the house?
The reason I ask is because I have since noticed problems in the house with the cieling lights. The house is 3 levels. We were working in the basement level tryign to steal power from the light fixture in the cieling. The middle floor is where the kitchen is. I notice my ceiling lights flicker quite often, and I think they are always flickering if any appliance is plugged into any socket (except the oven's socket. When I plug an appliance in the oven's socket it does not cause lights to flicker).
I have noticed on the top floor, my computer room light flickers too. I can also hear my UPS (which I have my computer tower and monitor plugged into) flicker turning on and off sometimes. Sometimes its not as bad as other times.
I have other rooms in the house but I dont spend alot of time in them. Im mostly in the kitchen and computer room most.
I remember looking at the wires after the sparks flew from the basement cieling where the light is, and a few of them looked burnt.
I dont know if my fuse box (its not really a fuse box, it has switches) has always sounded like it does, but I remember hearing electricity from it and it was not a constant buzz, but it sounded like something fluxuating.
I really dont know what to do now. I called the local power company to test the power connection from outside to verify that is okay.
Does it sound like something was damanged during my install?
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