Some examples from the web:

• I happen to have greater reverence for historical artifacts than you could ever imagine.
• I happen to have just the problem.
• I happen to have some very powerful friends at the Maury Povich show.
• I just so happen to have my GPS with me.
• I happen to have in my employ a most dependable soothsayer.
• I even happen to have a story about a man from Pawtucket.
• Only, I happen to have a photograph.
• Because I happen to have an opening in my schedule.
• I just happen to have been born to Persian Zoroastrian parents.
• I happen to have my talking stick...
• Actually, I just happen to have some time right now.
• They also happen to have amazing dumplings.
• I happen to have a knack of finding new members of that family.
• I happen to have an immaculately decorated guest room.
• I just happen to have my label maker.
• I happen to have a dictionary.
• I happen to have an old friend who specializes in that area.
• I happen to have just the thing for it.
• I happen to have an arsenal of hammers.
• I happen to have the same thing.

Some examples from the web:

• Edvard, we would have by chance a small diameter drill?
• They would have met by chance at a café...
• The difference in results between these randomisation subgroups may have arisen by chance in view of their limited sample size.
• We have arrived by chance where I live.
• Yes. Pat and Sally have stopped here by chance.
• There. I have here, by chance, some snapshot.
• Living creatures are too complex to have come about by chance; therefore, they must have had a designer.
• You haven't been chosen by chance.
• Firstly, Mr Arlacchi writes that health conditions have deteriorated, almost by chance, since we have been there.
• Do we by chance have any intimate couples amongst us today?
• I realise that these objectives are ambitious, but they are also realistic and have not been set by chance.
• The demographic crisis, human trafficking, global warming, cancer or terrorism have not just appeared by chance or overnight, nor did the problem of rising food prices.
• Have you by any chance seen two escapees?
• Have you by any chance seen a girl with short hair, a jacket...
• We have that chance tomorrow by voting for those amendments.
• You haven't, by chance, seen Officer Doughtery?
• You haven't by chance seen those pearl earrings that you bought me, have you?
• Yes. Listen, have you by chance seen a boy about ten years old, on his own, about this tall?
• They think they have a better chance by avoiding the aliens and finding a place to hole up.
• Have you by any chance seen two young men running around here tonight?