If you don't understand or can't troubleshoot the problem, you should get an electrcian PRONTO, RAPIDO.
If the wiring is aluminum. Yes to looseness. If copper, somebody might to have forgotton to tighten something.
Inability to turn off, go back to the first sentence.
When I bought my house inthe Carloina's it was only 7 yrs old and owned by a deputy sheriff. Somebody had bypassed the meter and I didn't find out until all of the power was 'supposedly' shut down and I was wiring in a ceiling fan and living room chandelier and the flashbulbs went off in a very dark attic.
A licensed electrician now works for me and worth every dime, even the days that we have to go fishin'.