Is this an electrical issue?

[Jack B.]

New tenant claims that they replaced the bulb in the downstairs bathroom and it flickered and so did the lights in the hallways outside of the bathroom. Is this an electrical short? What is it? Previous tenant never complained of such an issue. House wiring is NOT knob and tube. For what it's worth, the house I live in also does this sometimes. At least recently with some of the bulbs I replaced a few months ago.

Tenant said it was a 9.5 watt LED bulb when I asked type and wattage. There was an LED bulb in there previously he claimed  when asked, but it wasn't lighting up. He tried it in another socket and it worked. He said he put an incandescent bulb in the bathroom and it just burned out. He put a fluorescent bulb in there and it flickered then turned off.

I could have sworn when I was there a few days ago the light was working fine, I had all the lights one when I was doing a walk through, no issues.