Why does my ceiling fan light blink on and off after I turn it off?

Is your ceiling fan light operated by a remote control? It might be just a quirk with the brand of fan you're using - especially since there are no other lights experiencing the same problem. If you still have the instructions for the fans, you might find some answers in there.

I recently built a lamp. I want to run the wire from the fixture to the base through copper pipe. Is there any danger in using this pipe?

Technically, you are supposed to use only parts listed for that particular purpose. Copper piping is not considered a listed component.

Without seeing the lamp, it's hard to tell what you could use. Ideally, threaded lamp pipe works well, or you can use any of several other types of conduit such as EMT, IMC, RMC, ENT (if not needed to support the weight of the fixture) or even electrical PVC.

With regards to grounding, any exposed metal part on the fixture (frame, pipe, or otherwise) must be bonded to ground to divert any fault current that a user could inadvertently come in contact with.

Lately there has been a ceiling light in my house that keeps blowing bulbs. Why would this happen so often?

Premature bulb failure can be caused by a multitude of reasons such as power surges, loose connections, or vibrations.

You should make sure that the light fixture in question isn't being affected by movement, vibration or other motion (such as flexing floorboards on a floor above the light). If there are loose connections within the fixture, it can magnify any vibration problems. Also, if the light is part of a ceiling fan make sure that it is not wobbling. A light bulb suited for fan use would also help.

I have three outside lights on one switch. Last week one went out but it still doesn't work even with a new bulb. I tested the socket voltage and it is only 7volts. I took the fixture off so the wires were exposed and they were only 7 volts as well.

Sounds like you may have a loose wire connection somewhere else - possibly a bad neutral connection. Check at the other end of the wire - probably at another light location or where the switch is. Outside lights tend to have problems like this if the weather can get to the connections and oxidize them.

I have a fluorescent fixture in my basement that works fine all winter, but when the high humidity arrives, it stops working. Any idea why?