When you say you bought “expensive” bulbs, what kind were they? What kind/wattage of bulbs have you tried?

How is the light controlled? Photocell in the post, photocell somewhere else, timer, or just a simple switch?

A quick, easy “fix” is to clean and bend up slightly the tab at the bottom of the socket.

First step is to turn OFF the power at the service panel. Use a little fine (220 grit or higher) sandpaper or a green kitchen Scotchbrite to gently clean off any corrosion on the tab. Blow out any grit that may be left. Then take a small screwdriver and gently pry up the tab. Over time heat can cause the tab to loose a bit of it’s springiness.

Can’t guarantee it will fix your problem but it costs nothing but 10 minutes of your time.

Thank you, Mike. There is a light switch in the house that turns it on and off. Will have to use pliers to try and get the rest of the lightbulb out, but will try your fix. Thanks again.

Most premature bulb failures are caused by vibration. Try a rough service incandescent bulb and see if that last longer.

Here's a long shot. When 120 volt heating or large motorized appliances (space heater, toaster oven, iron, maybe water pump) turn on, do you notice that some lights in your home dim while others brighten?

It's OK if you get slight dimming, but brightening is a huge red flag. That would suggest a poor neutral connection, most likely at the main panel, though now and then it's found outside the house. Such a situation can cause high voltage on some circuits, and high voltage is another possible cause of premature bulb failures.

I've heard of the potato trick, but I've always found that carefully applying long-nosed pliers to the outside metal shell of broken bulb usually allows me to spin in free.

Rough service bulbs are a good thing to try, or get an (outdoor rated) LED bulb. That should also work and some of them are pretty amazing looking (simulating a naked incandescent filament).

I'm with Ron here. I've never had any luck with using a potato. It's kind of messy, too.

I make sure the breaker is off, then get in there with the long nosed pliers and mangle the darn shell. A little turning and twisting, and the job's done.

Once you have the old shell out, get some bulb grease at a good hardware store and apply a light coating to the base of the new bulb before installing it. That will keep it from corroding and getting stuck. The brand in my toolbox is Bulb EZ, but I expect that any good grade of silicone-based grease will do the job just fine.

Ron-

I have found that people who aren't highly skilled with hand tools (unlike you) tend to have trouble with using pliers to extricate the bulb remains, and sometimes screw up the socket in the process. The potato trick doesn't always work on a tightly screwed-in bulb base, but at least it does no harm to try it ;-)

Yup!

Parenthetically I would add that mashed potatoes are less effective in getting the socket out,

Stax-

Especially if they have gravy on them ;-)

Seriously, though, if you have to resort to longnose pliers, if you have space to use a pair of them, one in each hand, you can exert more even force and might even be able to unscrew it rather than mangle it. And you may reduce the chances of damaging the socket.

If by "expensive" you mean LED, they may not be the correct type. A lot of LED bulbs are ok for damp locations, but a lot of them are not listed for "enclosed" fixtures. A lighting store can probably put you on the right track.

This page has a lot of lamp post fixtures with LEDs.

https://www.lampsplus.com/sfp/8K557/?cm_mmc=GOO-SH--NA--NA-_-8K557&sourceid=DFGPD8K557&gclid=EAIaIQobChMIpPux3Zal5wIVyp-zCh3T1QbEEAQYBCABEgIrK_D_BwE